Hey...I'm new to this section. Just recently have I beeninterested in Human Evolution.

I caught a show on discover lastnight a show on the Aquatic Ape Theory. Anyone heard of this? Sounded very interesting. Don't really know if I absorbed it all. Let me know if I have the jist of it.

Before we were Human we lived in the Oceans and Seas like Dolphins and Whales do now. We began feeding on the fish and eventually this lead "us" to the shores where fish were more plentiful. The nutrience of the fish combine with the shores and time evolved us into what we are today?

I'm sure I am missing a lot of points but is this kinda what the theory talks about?

Also they were saying that most Scientist today are outraged a the new theory???

The theory goes against the traditional belief that we came down from the trees (our primate) relatives and evolved in a desert-like environment, which is why it is seen as bunk by most scientists. ~Something like that anyway.

sounds like you just didn't understand the topic, exept for the fact that scientists are outraged at the idea...
Seems to me that animals came out from the sea in a slow process of fish to amphibian to reptile to mamal. I can tell you that noone is ever going to find proof of an aquatic ape.... since there are no ape like creatures, nor do apes have any water related equipment (limbs/organs/other).

With dolphins and whales, they breath air. Apes have no kind of archetechture that suggests the ability to come up for air every couple minutes. Nor is there anything that an ape has that would be good at catching fish. NOR are there any fossils of like animals, NOR are there any non-extinct animals that remotly resemble an ape.

Evolution is not at all like a single animal, which is to say that an entire species does not leave the water to search for food, but small parts of the species break off and do what they do best (because otherwise they die), and the process from land to ocean is a VERY time consuming process involving many thousands of evolutions the size of ape to human.

An ape would have to have been in the water hundreds of millions of years ago to have evolved like that.

SO sounds like you got the idea, but the idea sucks.

I've heard of the theory. I read about it in an old book about mans evolution from the seventies or something so i never really knew if it was still an accepted theory. As i understood it, it was proposed as a reason for humans having lost all their hair except a little and changing to being bipedal. I don't think it tried to say that humans didn't originally descend from the trees, it just said that for a while we lived a semi aquatic lifestyle. Not nearly as aquatic as whales etc, but enough that it influenced our evolution a bit before we returned to land. Interesting, but i'm not sure whether i believe it, i haven't heard any recent studies that say it's true.

Frencheneesz , you're right again!
(though, there exist some non-extinct animals that resemble apes... but none of them live in aquatic environments)

That's the problem with discovery: half of the stuff is thoughtless theorizing by wannabie scientists.

"there exist some non-extinct animals that resemble apes"

LOL, one of those being ...... APES.

Just thought id let you know

Frencheneesz

Welcome to sciforums, Frencheneesz.

A little food for thought.

Mammals that live in the ocean are very few and limited. It is thought that it is possible that these mammals are the result of land creatures returning to the sea as mammals abound on land. That they reverse evolved from land to sea.

People, such as pearl divers show that exercise alone can go a long way towards improving the ability to hold your breath underwater and extend the time that it can be done. Add that to generation after generation until evolution starts to change the body into something more adapted to the new enviroment and you get something like the whale or dolphin.

interesting wet1

Thanks for the feedback everyone.

I suppose wet1, but evolution doesn't come out of excersize. No matter what your parents do to improove their stay under-water, it only matters what genes you get, not what kind of build your parents had.
Im sure i don't need to go into that. But not like it isn't possible that their were aquatic apes, it just sounds rediculous, and there certainly isn't much evidence for it, it just might explain the lack of hair we have......

Frencheneesz

"it just might explain the lack of hair we have......"

head....?

I believe that it was used as a protection from heat , but when we learned to walk on two, the haid gradually went away and only where it is needed it remained

we are still loosing hair I think

"I suppose wet1, but evolution doesn't come out of excersize. No matter what your parents do to improove their stay under-water, it only matters what genes you get, not what kind of build your parents had."

i dont see how it cant
genes are part of the human body, it changes when we change
diet, environment, intellectual stimulation will improve the human body and these newly aquired traits will be passed down to ones offspring.
are we not running faster? growing taller? its a two way street

the length of time is irrelevant, only whether it is possible or not

anyway as soon as biotech guys pinpoint the genes for growing gills, i am gonna tweak mine and head back into the oceans

ciao

eat this! (http://www.nature.com/nsu/020722/020722-10.html)

Actually spookz, evolution doesn't work like that.

We are getting taller (statistically) because we have better nutrition now that before. The main reason why many asians are short is not because of genes, but because of the food they eat. Rice does not have all the proteins that the body needs, and so if your diet consists mainly of rice, your bound to have deficiencies.
We are running faster more because of better running surfaces and shoes, and a little bit because of better technique, not because we are getting better DNA. I suppose food would help the running thing too a bit.

Your DNA does not change as you change, then only times DNA changes are anomolies in your body (radiation, and other splitting errors [mutation]), and when something reproduces.

When you get stronger muscles its because you have more muscle tissue, not because of your DNA.

Evolution does not work with improvements of the body, it works by "natural" selection. We humans have mastered something called cow selection. We pick the best cows and breed those, the worse cows going unbred. In this way, we speculate that the good cows will make good calfs, and since cows are pretty much fed the same and treated the same, the DNA is pretty much all there is.

The reason why something evolves is because one animal mutates one way, and another either stays the same or mutates a different way. The one that survives better stay non-extinct, and the one that is less adapted dies off. It is not because your traits are passed on, your DNA is passed on, not your body.
Frencheneesz

yes

if you look at this as something that happens over many generations perhaps
it might make more sense. it is not something that is readily observable in a single life span

if i am not quite making myself clear, the point i am trying to get at is what wet1 stated earlier

" Add that to generation after generation until evolution starts to change the body into something more adapted to the new enviroment and you get something like the whale or dolphin."

all the points you made are valid but is it the whole story?

eh. Its like the tootsie pop comercial. The world may never know.

:D
i sure as hell dont!


anyway here is how food binds to dna (http://www-bio.llnl.gov/mutagens/html/mutagen.frame.html)

Apes came from the sea like all other creatures. Because of predators or climatic changes over even a few centuries, some of these apes gradually managed to adapt through mutation, to survive by living in swamps/sea side, ect... & possibly back in the ocean for some time until land conditions improved again so that the aquatic ape decendants could move back to the land. This is probably the most likely scenario & is supported by the fact that there still isn't a good artifact/hominid--skull/skeleton example of the missing link between Chimps and humans.

This is a very dry perspective, on my part though. There is a lot more to consider when you take into account the many MANY environmental changes that have happened in the last 60 seconds of the Earth's history, relatively speaking of course.

I know I wrote about this last year or so:rolleyes::confused:

It seems like I also wrote about how the enviroment and other lifeforms interact so that the geologists and paleontologists could really predict what types of life would have existed, to a fair degree, even though they would not have a full fossil record.:rolleyes:

Seems like there was a discussion about the types of life that would exist on other worlds based on the climate & energy that would be present on other worlds.:)

There was some show I caught on TV long ago where a couple of scientist thought it was possible that we came from the sea and toted our sea with us internally. (ie, the ph is the same in our bodies as that of the sea itself)

The thought of the ability to increase the time underwater was mentioned with the thought that if this becomes your enviorment, only those who are successful at staying under might survive longer than those who could not, possibily leading to an evolutionary change.

Being as there are not many species that are aquatic mammals, it is likely that they came from land.

ahh
aquired traits are not the same as inherited traits
so i could practise holding my breath ,set the world record and still not pass the ability to do so to my offspring?


:D

quite right spookz. By the way was that a retorical question or an actual insight?

I would very much doubt that any "missing link" prooves anything but that we dont have enough information. What does show evidence against this aquatic stuff is the fact that there are no fossils (that i know of) of apes or ape like things under the water...

"Apes came from the sea like all other creatures"
I would say this was true if you are being metephorical. Apes came indirectly from the ocean as all other creatures probably have (no proof that things werent living in the atmousphere though).

I wouldn't trust a theory that says apes evolved under water THEN came to the surface. Apes have almost no adapted ways of surviving underwater. No gills, short air span, no flippers, not enough strength for long swims... Everything points away from your idea that apes started under water.

Frencheneesz

actual insight > aquired traits are not the same as inherited traits

rhetorical question > so i could practise holding my breath ,set the world record and still not pass the ability to do so to my offspring?

;)

dunno why french but i am not entirely satisfied. however its gonna have to do for now.

anyway i totally ignored the topic of this thread - aquatic apes!

:D

could make a good movie perhaps?
"return of the..........."

finally google (garbage in, garbage out!)
gives me something to bolster my

1- gut feeling
2 - lost memories
3 - logical reasoning
4 - etc


:D

If you remember your ninth-grade biology, you probably remember the Frenchman Jean-Baptiste Lamarck as one of the wacky also-rans of modern science. He was the predecessor of Darwin whose theory of acquired characteristics held that the stature of the giraffe came from generations of giraffe parents straining their necks ever farther to reach the leafy branches of the banyan tree, then -- and this was the wacky part -- passing their long necks on to their kids. For a century Lamarckism has been joke science, a notch below creationism, buried ever deeper under Darwin's theory of natural selection. But if a study published Monday in the influential journal Nature Genetics is any indication, Lamarck may be due for a rehabilitation, of sorts.

In the work published in Nature Genetics, Emma Whitelaw and her colleagues at the University of Sydney did a set of experiments with a particular strain of lab mice. The odd thing about this strain, which had been observed previously, was that despite being genetically identical, some of the mice were yellow, others gray-striped, others a mix of yellow and stripes. The researchers found that the differences were caused by subtle changes in the mice's DNA during their fetal development.

Whitelaw's even more surprising observation was that all the mice whose mothers had yellow coats always had yellow coats as well. In other words, the non-genetic change that occurred in the female mouse fetus was somehow passed along to her offspring when she became a mother. Even when the mouse embryos were nurtured in the wombs of surrogate mothers, their coat color was the same as that of the "genetic" mother.

Whitelaw's work is apparently the first showing that mammals can somehow pass along acquired characteristics to the next generation. It isn't quite as remarkable as Lamarck's giraffes inheriting stretched necks, but it is, strictly speaking, proof of Lamarckian inheritance.

The study is part of a growing field called epigenetics, a branch of developmental biology that investigates the mechanisms whereby certain genes are suppressed through changes in the chemical makeup and shape of the DNA in which they are embedded.

We all know how genes are supposed to work in the classic Mendelian scheme of inheritance: You get a copy or two of the fat gene, depending on whether or not it's recessive or dominant, and that makes you fat. Complicating matters, many conditions don't fit into a neat Mendelian box. It's known that schizophrenia is largely inherited, for example, but after years of unsuccessfully trying to locate single genes for schizophrenia, scientists believe that many different genes operating in different combinations contribute to the ailment.

Epigenetics adds yet a further complication to the picture. Instead of just a lot of genes operating together, it turns out, subtle, random changes in the chemistry of the DNA itself affect which of those genes actually fire into action.

Just how prominently epigenetics figures in the overall scheme of things -- how big a role they play, for example, in human traits and disease -- isn't yet known. But epigenetics studies have multiplied in the past decade and there is already clear evidence of epigenetic effects.

For example, many genes function only in men or women because of a gene-suppressing action called imprinting. Prader-Willi syndrome, a rare genetic disease, and Angelman syndrome, a neurological disorder, are both the result of subtle changes in the expression of a gene on chromosome 15. Prader-Willi manifests itself only when the DNA mutation is inherited from a father; Angelman syndrome from the mother.

In the nature vs. nurture debate, epigenetics falls under the category "the nurture of nature." As billions of dollars are poured into the Human Genome Project, it's worth pointing out, as does Eva Jablonka of Tel Aviv University, that "DNA sequence information is not sufficient for understanding the intricacies of biological inheritance." It's not that genetic effects aren't important, or the genome project any less valuable than its hype. Rather, scientists working on the fringe of genetics are pointing to some of the other factors that impinge on the success of genes.

So what does this have to do with Lamarck? It now appears -- Whitelaw's study is a good example -- that some of the alterations in gene function resulting from epigenetic changes can be passed along to the next generation. Ted Steele, another Australian scientist, made this argument strongly in a book he published earlier this year, "Lamarck's Signature: How Retrogenes are Changing Darwin's Natural Selection Paradigm."

Steele argues intriguingly that the coding for the production of antibodies to certain viral or bacterial attackers might be transcribed into the DNA of human somatic, or non-sexual cells, then somehow transferred from somatic to germ line cells -- sperm and ova. Steele presents a plausible case for such a transfer, but no direct evidence for it.

However, Whitelaw's article does present evidence for such a transfer. The yellow-coat color apparently comes about by means of an epigenetic change caused when a particle called a retrotransposon -- a gene that moves around the genome -- settles during fetal development in DNA near the color gene. How the retrotransposon was passed along to germ line cells, and thus inherited, isn't clear.

The patterns Whitelaw observed "seem heretical in their Lamarckian character," write developmental biologists Rosalind John and Azim Surani in an article accompanying Whitelaw's paper, "but they do occur and are therefore worth serious consideration."

As it happens, this kind of gene change has been shown to be quite common in plants, and is probably also common -- though harder to observe -- in animals, says Robert A. Martienssen, a scientist at Cold Springs Harbor Laboratory who has an article about plant epigenetics in the same issue of Nature Genetics. "To the extent there is Lamarckian inheritance, it occurs through epigenetics," he says.

Darwin, embarrassingly to the neo-Darwinians, was a great admirer of Lamarck (1744-1829) and incorporated his theories into work he published after "Origin of Species." The Stalinist agriculture czar T.D. Lysenko gave Lamarckism an enduringly bad name. Convinced that Lamarck was a better Marxist than Darwin, Lysenko gutted Soviet agricultural science and fruitlessly tried to improve grain harvests by experimenting with adult plants in the vain hope they would pass along the changes he made. Meanwhile, millions starved on collective farms.

But now that the Cold War is over, perhaps a neo-Lamarckian rebirth is overdue. Bring on the giraffes - By Arthur Allen Nov. 4, 1999

http://www.salon.com/health/log/1999/11/04/traits/

lamarck (http://www.ucmp.berkeley.edu/history/lamarck.html)

Environmental Influences (http://anthro.palomar.edu/mendel/mendel_3.htm)

Personality (http://psychlops.psy.uconn.edu/Personality/example2.html)

Apes did not come from the sea. Primate evolution took place on land. Also, there are plenty of fossil links between chimps and humans, and more are being found.

good research! I have just a couple of comments.

Lamarck is not considered "wacky." He was wrong, but not crazy or stupid.

I have read Steele's book and it's very good. His premises are very controversial.

Recently "Science" dedicated an entire issue to epigenetics.
http://www.sciencemag.org/feature/plus/sfg/resources/res_epigenetics.shtml#gen

Is the Aquatic Ape Theory credible ???



http://home.austarnet.com.au/stear/chimp_ss.gif

reply to AUSSIEABORIGINAL
Apes did not come from the sea. Primate evolution took place on land. Also, there are plenty of fossil links between chimps and humans, and more are being found.

In fairness to you, I understand what you mean sir. No, I didn't mean to say that apes came directly from the sea. Only amphibians could have made it across the barrier between land & sea. From these parent species of amphibians, all other forms of land based life evolved into the varieties of plants & animals that are present today. I was making the statement from this widely held assumption. Geez:rolleyes:


Primate evolution took place on land.
That's a very general statement. It is most likely that it did, given the paleontological evidence found thus far. But I am not going to state that this is even a 100% absolute fact. I do however assume it to be true until someone has a better theory.



Also, there are plenty of fossil links between chimps and humans, and more are being found
paulsamuel, I never said that there was no connection between chimps and humans, as I am aware that humans and chimps share over 99% of the same genes.

The theory is that some members of the primate family (apes) returned to the sea. Perhaps a population of primates didn't go to the jungles to become tree dwellers like most apes, but remained near the coastal areas living off of food gathered from the sea.

In time, some decendants of these "coastal apes" may have developed physical mutations that allowed them to gather food more successfully, or to evade land predators better than the other coastal based apes. These mutations may have included webbed feet and hands, as well as a lack of hair to aid in swimming. Also, the extra amount of body fat in humans has also been long held as another possible piece of evidence for the aquatic ape theory. With the exception of humans, the average primate cannot swim.

Physical mutations that do not hinder a living organisms ability to survive are usually passed on to the next generations. The successful decendants will inevitably interbreed, even if it is ten generations down the line. Thus the mutation of those genes increase, many times with offspring that cannot survive. But it is those that do survive and pass on traits that make such a thing as webbed feet/hands or increased body fat possible. These apes would have most likely been more like amphibians, living both in and out of the water. Perhaps not they or their following decendants ever did go any further than that. I am not suggesting that these aquatic apes further had decendants that lived entirely in the sea, but who knows. I am suggesting however, that some ape decendants would have become separated from the root family of primate with one branch heading for the jungles/savannas and the other continuing to live in/around the coastal waters.

Perhaps gradual climatic changes or an increase in predators caused the amphibian ape & the jungle ape to remain successful, while some other primate variants may have continued to diminish in numbers until becoming extinct entirely. Many years later these amphibian apes may also have lost their ability (edge) to survive for the same previously mentioned reasons and their land adapting decendants gradually lost many of the traits of it's amphibian predessors as it became more land based again. Humans.

I could write a ton more....and will if these points aren't understood or I haven't been clear. Actually I have just gone into a very general point of view regarding this. To go into even a fair amount of detail, with supporting evidence, I'd have to write my own book & porfiry is already getting depressed over the amount of webspace used so far:confused: Great subject!

ps....wet1...Is this the kind of serious science discussion that you said you have longed for recently?/? :D ~~~Evolution Rules~~~!

evidence of aquatic apes (http://www.geocities.com/jjnevins/namor.html)



*a probable land to sea scenario

"Vestigial structures are leftover, homologous, evolutionary, "baggage" with little or no current function. They are historical remnants of features that served important uses in ancestors. Stephen J. Gould calls them "senseless signs of history" because an organism shouldn't have them unless it has an evolutionary history.

For example, whales and some large snakes have internal remnants of hind leg bones that reflect their evolution from four-legged ancestors.

The young of blood-drinking vampire bats have molar teeth, indicating their derivation from ancestors that chewed.

Vestigial features also strengthen the scientific basis for evolution because they permit us to make predictions, one of the basic components of the scientific method. For example, whales are warm-blooded, air-breathing animals that we classify as mammals. The anatomy of mammals in general suggests that, if evolution has occurred, the original mammals lived on land and whales became modified for living in the sea. Having found vestigial hind leg bones in whales, we predict that we should find whale fossils with better developed hind legs that show how whales might have evolved from land-dwellers to swimmers. Such fossils have been found."

http://www.nova.edu/ocean/biol1060/evolution3.html



"Confirmation:
Probably the most well known case of atavism is found in the whales. According to the standard phylogenetic tree, whales are known to be the descendants of terrestrial mammals that had hindlimbs. Thus, we expect the possibility that rare mutant whales might occasionally develop atavistic hindlimbs. In fact, there are many cases where whales have been found with rudimentary atavistic hindlimbs in the wild (for reviews see Berzin 1972, pp. 65-67 and Hall 1984, pp. 90-93). Hindlimbs have been found in baleen whales (Sleptsov 1939), humpback whales (Andrews 1921) and in many specimens of sperm whales (Abel 1908; Berzin 1972, p. 66; Nemoto 1963; Ogawa and Kamiya 1957; Zembskii and Berzin 1961). Most of these examples are of whales with femurs, tibia, and fibulae; however, some even include feet with complete digits. "

http://www.talkorigins.org/faqs/comdesc/section2.html



"Scientists also rely on embryology and biochemistry to understand evolution. Embryology is the study of the early stages of an organism's development. Embryo's of related organisms develop in similar ways. All vertebrate embryos have folds of tissue in the neck region called gill pouches. These folds develop into gill slits in fishes. Mammals never develop gills but the pouches appear in their embryos. They are thought to be inherited from a common ancestor"

http://mws.mcallen.isd.tenet.edu/mchi/ipc/Biology/bioch10htm/bioch10sec3.htm

the last link can obviously work for both theories (conventional and aquatic)

>pseudoscience ;) (http://www.straightdope.com/mailbag/maquaticape.html)

Well, I can forget about writing the book.....

You pretty much summed it up right there:cool:

You should have posted this earlier. You would have saved me the trouble of muddling through my thoughts:rolleyes:

To hell with this:( , I've got to go mow the lawn!

ps...edit note: Sorry wet1, I missed your quote in your previous post about reverse evolution earlier.
Mammals that live in the ocean are very few and limited. It is thought that it is possible that these mammals are the result of land creatures returning to the sea as mammals abound on land. That they reverse evolved from land to sea.

You said, "Only amphibians could have made it across the barrier between land & sea." This is wrong, fish do it, right there in Australia, mudskippers.

You said, "I never said that there was no connection between chimps and humans," but, you specifically said missing link. There is no missing link and the phrase is very antiquated, over 150 years old. It has no meaning today.

The aquatic ape theory is no theory at all, just a bunch of "just-so" stories with no supporting evidence. Some specious evidence used to support it is "With the exception of humans, the average primate cannot swim," which is just plain crap. The average human can't swim, unless taught, and I'd bet that primates can be taught to swim, just like us.

You said, "Physical mutations that do not hinder a living organisms ability to survive are usually passed on to the next generations." This is wrong. There are inummerable instances where deleterious mutations are retained in populations, for inummerable reasons.

I don't think you need to write "a ton more" on this subject. Next we'll be discussing the evolution of flying pink elephants.

good research!

You said, "Only amphibians could have made it across the barrier between land & sea." This is wrong, fish do it, right there in Australia, mudskippers

Well damnit, what is an amphibian? Are you saying that the mudfish is not an amphibian because it is "called" a fish? Don't you see that you have provided a great example of what I was writing about before you decided to dismiss everything I have attempted to communicate because you think that you found an ill dotted "I" & an occasional uncrossed "T"? :rolleyes: Surely you don't think that all land animals began on land & then moved to the sea, do you?

I'm sorry, paulsamuel, I don't mean to be cross.


You said, "I never said that there was no connection between chimps and humans," but, you specifically said missing link. There is no missing link and the phrase is very antiquated, over 150 years old. It has no meaning today.
:rolleyes: :rolleyes: :rolleyes: :rolleyes: paulsamuel, ...:rolleyes: .. I have sat here for several minutes, trying to find a way to say this, in a way that you can understand, & still avoid ......:rolleyes: ...ANYHOW HERE GOES

.....unless every generation of every specie that has ever lived has a full & complete level of genetic documentation done-- presumably by modern human beings--then it is a missing link.

I realize that you are assuming that I am living 150 years in the past, sir. I assure you that I am not. I do not hold with the old Lamarck theory & believe it or not sir, I also do know about indoor plumbing!


You said, "Physical mutations that do not hinder a living organisms ability to survive are usually passed on to the next generations." This is wrong. There are inummerable instances where deleterious mutations are retained in populations, for inummerable reasons.

paulsamuel, you just cut your own ass on that one, buddy. First, you disagreed with my saying that mutations that are not harmful will be passed on. Then you came right back & said these "mutations are retained" ....for inummerable reasons.

A little advise.....this is a science discussion forum, not the "Gong Show." If it were, I would not be the contestant & you are not the "Unknown Comic."


:D

I'm not going to argue with you, if you want to call a fish an amphibian, go ahead.

Fossil links between apes and humans are well established.

I'm not sure how you're bringing Lamarck into this, but don't be so quick to dismiss the inheritence of acquired characteristics. There is evidence that, in some cases, it happens.

Mutations, both beneficial and harmful, can be inheritied. These mutations are not isolated, they are passed on as a set.

Take a pill.

The so-called "missing links" is in fact also called "The Swedes" :D

:confused: :confused: :confused:

It's a joke coz Benelina was reading it before.

This argument has been done to death (on the net especially).
See the Talk Origins Archive wich contains the original usenet archive and a faq on evolution.
http://www.talkorigins.org/

Is the Aquatic Ape Theory credible ???

Are You Credible? What Are Your Credentials?

And What Does Q stand for? Queerboy? or Quantumphallus maybe?

TeeHee! ^ - ^

And What Does Q stand for? Queerboy? or Quantumphallus maybe?

I must confess, I've never been skewered by such rapier like wit. You must have stayed up all night preparing this well written response. Keep up the good work. ;)

"quote:
--------------------------------------------------------------------------------
Is the Aquatic Ape Theory credible ???
--------------------------------------------------------------------------------



Are You Credible? What Are Your Credentials?"

Now, I don't usually appreciate Q's sarcastic responses, but you take the cake. Q is not a theory and thus does not need to have evidence. This ape theory needs evidence, so the question is: What evidence is there for this?

Credentials are for employers who do not want to get to know you and how smart you are. Credentials are not important, i can give evidence for this, if Bush can go through Yale and become president, then credentials are bogus. The only thing that is important is that he gives good ideas and has accurate facts.

I was particularly irritated with your remarks about his name. Those kind of low remarks only make you sound like an idiot. So you called him queer. Why do you feel you have to make yourself sound stupid just to insult him, huh?

grow up girl.

Aaaaahh now I see. queerboy was meant to be an insult.

In what sense is referring to someone's gayness an insult?

"In what sense is referring to someone's gayness an insult?"

Uhh, don't get down on me! It is in the derogetory sence as calling someone a female dog is an insult. Surely you can understand the simple workings of a crude mind such as this "photon girl" 's.

If i had to agree with one og these theories then it would be that we all evolved from fish and therefore came from the sea. However. Proof of this will not be found as someone has said. This is becuase it is not the truth. i actually know how we came into being and where we came from.The truth is this:
In the beginning God created the heavens and the earth.The earth was barren, with no form of life;it was under a roaring ocean covered with darkness.But the Spirit of Godc was moving over the water...... LOL :D :p
God said, "Now we will make humans, and they will be like us. We will let them rule the fish, the birds, and all other living creatures." So God created humans to be like himself; he made men and women. :D

Aquatic ape theory? SEA-MONKEYS!!! :D

Sorry... :p

>>>>>>Aquatic ape theory? SEA-MONKEYS!!!

LOL!!:D

So, there are no fossil records of the "aquatic ape".
Ever wonder why?
Coastal mammals.
How many fossils of coastal mammals have fossils?
Waves do wonderful things to surfaces of bones. Like wears them down and deforms them and eventually removes them from the fossil record because the sea board shifts constantly.
Then you talk about the fossils we have of whale ancestors. Found in deserts. In deserts that used to be oceans. Thousands and thousands of years ago. Actually more like millions but my prehistory is a little fuzzy right now. So the places where the fossils would be are in one of 2 places, the ocean floor (when was the last archeological dig you saw in the trenches of the ocean?), or under the current shifting coastal sand bars. Do you know how hard it is to dig there? You get wet sand in your shoes. It sucks. Last time I tried it I found a sea shell. It was neat. Anyway. Go dig. You'll see what I mean. Of course you could also look at the coastal ape behavior studies (sorry, saw it on Discovery channel and I'm too lazy to look up an href). But these monkeys that were trapped in a coastal area adapted to catching and eating fish. Known attribute of fish. Causes advanced development of the brain. Eat a fish sandwich, read a book. You'll remember it better (okay, you can flame that one, it's weak, but there are studies on it). But anyway. So I like the theory. It makes sense to me since it fills in the blanks for a lot of things. And I studied the chaos theory as it applies to evolution. Pick you random variables and watch the fun. Works out pretty well.
But anyway.
Later I'll actually think about coming up with better answers. It makes sense, and even jives with a lot of Darwins theories. Don't bash it unless you study it more. I will admit that the Discovery show was very crappy. It doesn't make things very concrete as far as evidence and they got very side tracked with a lot of things. Anyway. Brain tired. Go sleep now.

you said "So, there are no fossil records of the "aquatic ape".
Ever wonder why?"

I know why, there are none.

then you said, "How many fossils of coastal mammals have fossils?"

I presume you meant species of coastal mammals as fossils don't make fossils. There are tons of examples of fossil evidence of coastal mammals. In fact, all marine and aquatic mammalian species have a fossil geologic history. A good example; on the coast of North Carolina thousands of phocid fossils have been found and have been used to reconstruct phocid evolutionary history.

Next:
A study of coastal extant monkeys is not evidence of an aquatic ape.

Next:
You call it a theory, but I don't think it is, in a scientific sense. Read Popper, Kuhn and Mayr and you'll see what I mean.

Finally:
It makes NO sense, fills in NO blanks and does not "jive" with evolutionary theory.

You might want to read some evolutionary biology texts, may I suggest Futuyma.

good luck

"Then you talk about the fossils we have of whale ancestors. Found in deserts. In deserts that used to be oceans."

Well, ya. Wheres the monkeys in that picture?

"Do you know how hard it is to dig there?Do you know how hard it is to dig there?"

Most scientists don't do it for the glammer (damn spelling). Theyll find a way around the mud.

"And I studied the chaos theory as it applies to evolution."

Where did you go to school? Chaos theory is not actually a theory. Chaos theory is the scientific equivelant of God. There isn't really any evidence for it is there? I actually don't know much about the chaos "theory", but that it says that things are chaotic and noone can explain it. Its the theory the greeks had, much better than religion; whoever thought of THAT was a bad planner.

Considering you actually studied chaos theory, it doesn't surprise me that you belive this theory. The way you write makes it seem as if your open minded though, weeiiirrdd.

If we ever came from the sea while mammals it was before we were little tree-shrews. Our evolutionary line is reasonably well mapped after that.

there is reason to beleive that this theory could be valid because when babys are born underwater they can stay there for quite some time and also because the placenta in wich they live as unborn life forms is filled with ambiotic liquid.

"there is reason to beleive that this theory could be valid because when babys are born underwater they can stay there for quite some time and also because the placenta in wich they live as unborn life forms is filled with ambiotic liquid."

No no no. Do we have gills? no. Can we survive underwater? no. Do we have any inable biological machinery that could have possibly been used to breath underwater? no.

Feti do not breath the ambiotic liquid. They get their oxygen through the umbilical cord. How long does a baby last when born under water?

A baby born underwater may drown. Every air-breathing creature that can, gives birth or lays eggs ON LAND.

The prime fact is that we cannot breathe underwater, and monkeys cannot either. Ambiotic fluid contains no free oxygen and, in any case, is not breathed.

I am appalled that anyone can actually look seriously into this theory. Get an education.

I can't take the theory serious, but now I have to defend it.

Whales (and dolphines, in a sense seals, etc) are born in the water, and live most of their lives underwater.
Still they have lungs, not gills. The aquatic ape theory does not necessarily require gills.

I must add that this :"there is reason to beleive that this theory could be valid because when babys are born underwater they can stay there for quite some time and also because the placenta in wich they live as unborn life forms is filled with ambiotic liquid." is nonsense.

"The aquatic ape theory does not necessarily require gills."

Ok thats true. BUT it does not make the fact that babys grow in a fluid applicable to the theories support. What does develpment have to do with after birth life anyway? Do things seek areas that are like their birthal environment? I think not.

:D
" Do things seek areas that are like their birthal environment?"
polar bears do...
and maybe eagles.

"polar bears do... "

In what way?

If you look at it from an evolutionary standpoint, it is simply impossible for that to be the case. Noone remembers that they were growing in a liquid, we now know that only through reasoning, which animals simply do not have enough of. Not only that, there is no advantage to seeking a lifestyle in that of the way they were grown. It simply has no affect on evolution.

in that the average temperature of the polar bear womb -20 degrees C is.
And eagles have large eggs, so that the unborn chicks can fly arounbd a bit. Just to practise.

"in that the average temperature of the polar bear womb -20 degrees C is.
And eagles have large eggs, so that the unborn chicks can fly arounbd a bit. Just to practise."

Polar bears do not HAVE to seek an environment that is -20 degrees, they live in it. It is pure coincidence (from an evolutionary standpoint) that their womb is the same or close to the same as the outside air. And unborn eagles can't fly in their eggs, period.

Evolution HAS to happen based on natural selection. How would an animal searching for an environment like it growed in help them survive? And how would they KNOW what the womb was like? Can you remember what the womb was like when YOU were in it? Do you suddenly have the urge to live in a swamp or something because you know that your original residence was watery? I doubt it.

I always thought that Polar bears are born in Nigeria and migrate to the arctic area. Hmm maybe I was wrong :D

and their wombs are actually something like 37 degc. C

I already do live in a swamp: the Netherlands

it's amazing how many outcries there were against the aquatic ape theory in this topic. I actually how many of these people were actually scientists.

The interesting thing about the aquatic ape theory is that it explains several morphological features of the human species that are difficult to explain otherwise. That is the scientific merit of the idea.

It would be very plausible (in the sense that it is logical) that the human species spend a relative large amount of time near water during specific stages of the evolution of the human species. While fouraging in the water (maybe in coastal regions) it could have been an advantage to have several adaptations to the water environment. Hence there might have been a selective pressure at some period during human evolution for water adapted structural changes.
There might be no conclusive proof and the scientific community might have been extraordinary sceptical about the idea when it came out, but that doesn't mean the idea didn't have any merit to it, or that it was just plain silly.

people..there is no right or wrong in science, unless the majority thinks it is wrong, but it still could be right.

and we might end up adapting some parts of the aquatic theory in the end when the dust clouds have settled.
http://members.truepath.com/sapphoo/horse.gif

The proponents of the Aquatic Ape Theory (AAT) have classically argued this theory based on Lamarckian reasoning. Unfortunately for them, it has been proven unequivocally false due to the advent of molecular biology.

"it's amazing how many outcries there were against the aquatic ape theory in this topic."

Its amazing how many people thought it mades sense....

"The interesting thing about the aquatic ape theory is that it explains several morphological features of the human species that are difficult to explain otherwise. "

THIS i doubt. What morphology features?

"It would be very plausible (in the sense that it is logical) that the human species spend a relative large amount of time near water during specific stages of the evolution of the human species."

Animals always stay near water. Why? Well, its because we need H20 to survive. We don't need to live in water to drink it you know. The reason why have water impermiable (mostly) skin is so that we can keep that water inside us that we would have gotten redily IF we lived in the water.

"There might be no conclusive proof and the scientific community might have been extraordinary sceptical about the idea when it came out, but that doesn't mean the idea didn't have any merit to it"

Not only that, but it simply doesn't make sence. And an idea that doesn't make sense doesn't have any merit.

"people..there is no right or wrong in science"

What science are you talking about? Opinions? Science is all about right and wrong (as in correct and incorrect).

The aquatic ape hypothesis is completely perposterous and would never have happened. Once again, WHAT ADVANTAGE FOR SURVIAL WOULD IT BE FOR APES TO LIVE IN WATER???

+++The aquatic ape hypothesis is completely perposterous and would never have happened. Once again, WHAT ADVANTAGE FOR SURVIAL WOULD IT BE FOR APES TO LIVE IN WATER???+++


easily accessible, reliable food source (coastal region)...


i'm not going to respond to everything in your previous post, but i shall just concentrate on a few things.

By aquatic we shouldn't immediately assume totally aquatic. We also might think about it in terms of semi-aquatic. Even though the original idea might have been lamarckian we can still take this notion and contemplate the merits. There is nothing unscientific about that.

One thing we could think about is the upright posture of humans. One can wonder how this feature has arisen. One postulation is that by living a semi-aquatic it might have been advantaguous to stand upright instead of standing on four feet. The obvious advantage here is height. By standing upright you can traverse deeper water by still walking, decreasing the risk of drowning. Furthermore, the uplift effect of water would have facilitated the transformation to a bipedal posture. Nobody says here that this is the way it happened, but it would be unscientific not to examine these notions or not think about them.

and the features that the aquatic ape theory tries to explain:

Lack of Hair
fat
bipedalism
Voluntary Breath Control
Descended Larynx
crying of babies...
http://members.truepath.com/sapphoo/horse.gif

Spurious

By standing upright you can traverse deeper water by still walking, decreasing the risk of drowning. Furthermore, the uplift effect of water would have facilitated the transformation to a bipedal posture

ATT's theory of human bipedalism, which maintains that bipedalism was developed to "keep its head above water", though the theory fails to say exactly why this is an advantage. Clearly, though, this can only an issue when the water is relatively deep, say up to the shoulders. (Modern apes have short legs and long arms, leading to a distinct slope of the body when knuckle walking.)

A creature standing upright in this depth of water would have its legs and lower abdomen submerged and wading in this depth is both slow and inefficient because of drag. This would make flight from predators quite difficult. Swimming is a much more efficient form of locomotion in water of this depth and this precludes a bipedal gait. (You can confirm this yourself next time you are in a swimming pool.)

The only animals known to be both bipedal and aquatic are some birds, where bipedalism is a necessary adjunct to the development of wings. Consequently, we have to say that bipedalism is not a known characteristic of aquatic animals.

Lack of Hair

Humans are, of course, not hairless. The hair over most of our bodies is quite dense in terms of follicles per unit area - similar to most apes in fact. However, the hair in most cases is short and fine. In some areas of the adult human body, hair is prominent (pubic and underarm hair) and on the head it is far longer than the hair of any other primate. In many human males, a sizeable mane would cover the entire head were it not for the fashion for shaving and trimming.

The closest to hairless would be cetaceans - whales and dolphins - which are extremely streamlined creatures with a totally submerged, completely aquatic lifestyle. (In fact even they retain cilia which are important to prevent the boundary layer around their bodies from detaching and producing drag. ) Seals are incorrectly cited as being hairless (Ever heard of the fur seal?) and of course creatures such as otters and beavers have fine pelts. On the other hand, rhinoceri, elephants and armadillos are land animals with only vestigial hair.

fat

In reality, the natural human fat distribution is not something about which a great deal can be said in concrete terms. Firstly, we only know fat distribution for modern, relatively obese, Westernized humans. Secondly, we do not know the fat distribution for wild apes, only the obese specimens in zoos. However, we can examine the AAT claims that human fat distribution is characteristic of aquatic animals and that the purpose of human fat is insulation.

Human fat forms a continuous subcutaneous layer. This is a fallacy. Like most mammals, human fat occurs in about a dozen "depots" around the body. In many humans, these depots have expanded and overlapped so that they create the illusion of a continuous subcutaneous layer. However, this is a characteristic of obesity and is not true of all humans. The depot-based distribution is characteristic of all mammals, including the aquatic ones, so it is quite incorrect to say that human fat distribution is characteristic of aquatic animals.

The second fallacy is that the purpose of the fat layer is insulation. This again is based on a widespread fallacy. Surprisingly, there are no animals in which fat plays a significant insulating role. Measurements taken on seals indicate that skin temperature of fur seals is only slightly lower than core body temperature even after prolonged immersion in cold water. It appears that stagnant water trapped in fur is an excellent insulator, and that arrangement of muscle tissues plays a far more significant role.

Furthermore, fat distribution in humans appears unrelated to the heat production of the organs beneath, e.g. there is relatively little fat on the head even though most of the body's heat is lost through it.

"easily accessible, reliable food source (coastal region)... "

easily accessible? in what way? Reliable food sources can be found anywhere that life grows. And it would be a bit tough to actually find easy food sources for an ape-like creature on the coast of the ocean. what would there be to eat? Clams are too hard (needs a bit of intelligence to actually use it efficiently), but perhaps. And there are fish, but no edible plants or large animals. Don't you think the land has quite enough resources for food. Look at the apes in the congo. Natural selection requires the non-reproduction of "less suited" animals, but apes that didn't look for food in the ocean would surely find food on land.

"By aquatic we shouldn't immediately assume totally aquatic. We also might think about it in terms of semi-aquatic. Even though the original idea might have been lamarckian we can still take this notion and contemplate the merits"

Thats reasonable

"One postulation is that by living a semi-aquatic it might have been advantaguous to stand upright instead of standing on four feet."

That would be a very nice reason for the evolution of uprightedness IF we had needed to be in the water and could not swim. These things are, as far as I and the evidence that has been given is concerned, not justfied for happening.

"but it would be unscientific not to examine these notions or not think about them. "

Who says we haven't? This isn't quite a fresh theory.

"Lack of Hair "
___________

Why would lack of hair be an advantage to a sea creature? Streamlinedness? Well, if we could swim, than it might be an advantage, but only in that case. And the uprightedness arguement would break down if you tried to use this.

"fat"
_____

Everyone needs fat. Come on, humans and apes are not the only land animals that have fat in such quantities....

"bipedalism"
___________

A direct effect of uprightedness, so they are linked.

"Voluntary Breath Control "
______________________

I think a much more feasible explanation is that we need to eat though our mouth. If we didn't have voluntary breathing control, we would all mostly choke to death on our food, not on water.

"Descended Larynx"
________________

Again, directly related, but to voluntary breathing control.

"crying of babies"
______________

What about this? I don't know why babies would evolve crying because we live in the sea.... Most mamals have babies that cry. Thus it is an unrelated argument unless you want me to believe that this is now the "Aquatic Mamal, Bird, and Reptile Theory".


Its great that you are thinking about new ideas, but you should not accept them without substantial evidence that is relevant. So far, even if this theory explained all those things you listed, you still have not given us a good advantage for living aquatically.

Human bipedal running is both slower and less energetically efficient for running than is chimpanzee knuckle-walking

However, for normal walking locomotion, for instance from one food source to another, human bipedal walking is more energetically efficient than is chimpanzee knuckle-walking

Bipedalism would confer an adaptive advantage especially in times of low food availability and sparse distribution of food resources

Bipedal humans would expend less energy to move from patch to patch of food, and would get there faster on average than knuckle-walking early pongids

In a changing environment such as that found at the close of the Miocene, food resources became more sparsely distributed as forests shrank and expanded

The ability to move from one forest patch to another efficiently would have been adaptive

Bipedal hominids would have been well suited to do this
<table border="1" cellpadding="0" cellspacing="0">
<tr>
<td align="center" colspan="4" width="394"><b>Energy
Efficiency</b></td>
</tr>
<tr>
<td align="center" width="106"><b>Walking speed</b></td>
<td align="center" width="72"><b>Species</b></td>
<td align="center" width="102"><b>Energy cost ml 02/kg/hr</b></td>
<td align="center" width="114"><b>Energy cost relative to
quadruped</b> </td>
</tr>
<tr>
<td align="center" width="106"><b>2.9 km/hr</b></td>
<td align="center" width="72"><b>Chimp</b></td>
<td align="center" width="102"><b>0.522</b> </td>
<td align="center" width="114"><b>149%</b></td>
</tr>
<tr>
<td align="center" width="106">&nbsp;</td>
<td align="center" width="72"><b>Human</b></td>
<td align="center" width="102"><b>0.193</b> </td>
<td align="center" width="114"><b>86%</b></td>
</tr>
<tr>
<td align="center" width="106"><b>4.5 km/hr</b></td>
<td align="center" width="72"><b>Chimp</b></td>
<td align="center" width="102"><b>0.426</b> </td>
<td align="center" width="114"><b>148%</b></td>
</tr>
<tr>
<td align="center" width="106">&nbsp;</td>
<td align="center" width="72"><b>Human</b></td>
<td align="center" width="102"><b>0.170</b> </td>
<td align="center" width="114"><b>94%</b></td>
</tr>
<tr>
<td align="center" colspan="4" width="394"><b>2.9 km/hr is
normal knuckle-walking speed of chimps, 4.5 km/hr is
normal bipedal walking speed of humans (Rodman and
McHenry 1980)</b> </td>
</tr>
</table>
</center></div>
(dr bindon)

?

I would suggest that instead of thinking of African apes as being bipedal, it would be better to think that they had an unspecialised form of locomotion similar to that of Orang Utans. Orang Utans do not come to the ground often, but when they do they get around sometimes by fist-walking and sometimes by ungainly upright walking.

If you can imagine an ape like an Orang Utan, sleeping in trees and spending much of their time in trees but coming to ground occasionally, this could be a model of early African apes. This would be similar to the life-style of some lowland gorillas today. Lowland gorillas are tempted into bais in the rainforest, which are areas of open but often swampy ground, to feed on the abundant aquatic vegetation. However, early African apes would not have been good cellulose-digesters like modern gorillas, but would have been tempted down from the trees by the starch-rich roots of aquatic plants.

Never having to walk long distances and often having to wade in an upright posture, this unspecialised form of locomotion would have been quite adequate for their purposes. One population would have specialised in drier ground and became the ancestors of the gorillas. Needing a more efficient mode of locomotion, they became knuckle-walkers. Later the ancestors of the chimpanzees became another offshoot, and followed a similar path.

This left our ancestors, who when they expanded out of the marshy conditions were now so adapted to an upright condition that it was natural that they should adopt bipedalism instead of knuckle-walking as their mode of locomotion. Even so, the Australopithecines continued to sleep in trees and continued to spend much time on the flood plains of East African rivers like the Awash.

Early Homo would have been more wide-ranging and would have developed bipedalism to the efficient form that we see today. Homo would have continued to wade when necessary but would also have developed swimming and diving skills. They would have done this not only to get food but to move across a landscape and survive flooding. They would have exploited not only rivers but also lakes and the sea.

The last common ancestor of humans and chimpanzees was 5 or 6 million years ago. It is only natural to suggest that it was this time that was the most significant for human evolution. However, it could be that this age was of no importance, and nothing of any great significance occurred. Instead, two other times were important. One was 10 or 12 million years ago and the other was 2 or 2.5 million years ago. The first was the time when an ape similar to the Orang-Utan started coming down to the ground regularly to exploit a wet landscape. The other was when early Homo became fully bipedal and exploited marine and grassland habitats, possibly with a seasonal migration. The Australopithecines probably lived pretty much like their ancestors, and some lowland gorillas today. 10 million years or so that our ancestors spent living like this, wading around a wet landscape, could be seen to be a preadaptation to the marine exploitation of Homo.

Whatever the origins of bipedalism, it seems likely that at some point bipedal apes would have been in competetion with quadrupedal apes. Our ancestors would have been in competition with the ancestors of chimpanzees. Bear in mind that early bipedal apes like Australopithecus were very similar to chimps except they were bipedal. How is it that bipedalism survived, given its obvious disadvantages. This is a question that Elaine *Morgan and Marc *Verhaegen fail to address.

Bipedal apes could not run as fast as quadrupedal apes. They were not as good climbers. So it would have more difficult for them to avoid predators. However, bipedalism is more energy efficient at walking. If our ancestors made use of their ability to walk long distances then they could have competed against the chimps. So I think that Australopithecus and sister genera were wide-ranging generalists. Also, they would have continued to have an advantage in watery environments like flood-plains. (andrew lewis)

There are two views about East Africa

1. East Africa was once covered in rain forest of the type still seen in west and central Africa. During ice ages it became drier. Rainfall decreased 5 million years ago and even more 2.5 million years ago. Five or six million years ago, when the first hominids - Ardipethecus and Australopithecus - appeared, there was not much savanna.

2. The mosaic of grassland, woodland, and patches of forest which exists today has characterised the region for at least 15.5 million years. See *'Africa A Biography of the Continent' by John *Reader, page 52.

There are three ways of viewing East Africa today.

1. A vast grassland plain.

2. Zones or belts of vegetation of different types, dependent on differences in rainfall, from woodland to grassland to desert.

3. A mosaic patch-work quilt of vegetation of different types.

All three views have their value, but the third is the most correct, especially of the Rift Valley where most hominid fossils have been found.

The boundaries between adjacent vegetation zones are extensive. Bernard *Campbell in his book *'Human Ecology' writes about the boundary between forest and woodland, what he calls the 'forest/woodland ecotone'. He explains that this boundary is very extensive due to natural irregularities of altitude and rainfall, and by the presence of forest along the river beds which cross the more open plains. He says that a species living at the junction of two biomes can exploit two sets of resources, which is especially important during a time of seasonal dearth of food in one of these biomes. Woodland, as distinct from forest, is seen by many as an important biome for hominids. What is true of the forest/woodland ecotone is true of other ecotones.

People have pondered which habitat produced our ancestors and ultimately us. As generalists, our ancestors were more likely to have inhabited an ecotone between two vegetation zones than one zone or habitat. They are even more likely to have inhabited a region where many zones and many ecotones are found together. This would be in the flood plains of east African rivers where so many hominid fossils have been found. Here gallery forest is found along the rivers and especially in the bends of the meanders and the islets between the branches. Woodland and grassland would be further away from the river. The sides of the valley would have another vegetation type. True mosaic. Trying to say which habitat or vegetation zone hominids were in is a futile task, because of the concept of ecotones and flood-plain mosaic. Migration is another complicating factor. Also, we should be talking about population densities for different regions, not where they were and where they weren't.

Flood plains did not only exist on the coast. This is what John *Reader has to say about it in *'Africa A Biography of the Continent' by, page 73.

At times the ancestral Omo flowed through the basin and east to the Indian Ocean ( a connection which is confirmed by the presence in the Turkana deposits of fossilized ocean fish remains, such as the teech of a stingray). At other times its waters remained in the basin in the form of rivers flowing down the length of the basin like tangled braids of hair, meandering through gallery forests and woodland; creating floodplains and ephemeral lakes.
Nina *Casimati in her book *'A Guide to East Africa' writes eloquently about Lake Manyara National Park and Serengeti National Park and their many distinct vegetation zones.

This is the kind of complex region that in my opinion is the most likely to have evolved hominids. (andrew lewis)


A quick background to the Pliocene (http://www.esd.ornl.gov/projects/qen/pliocene.html)

Originally posted by (Q)
Spurious

By standing upright you can traverse deeper water by still walking, decreasing the risk of drowning. Furthermore, the uplift effect of water would have facilitated the transformation to a bipedal posture

ATT's theory of human bipedalism, which maintains that bipedalism was developed to "keep its head above water", though the theory fails to say exactly why this is an advantage. Clearly, though, this can only an issue when the water is relatively deep, say up to the shoulders. (Modern apes have short legs and long arms, leading to a distinct slope of the body when knuckle walking.)



i think they said this because some ape/monkey species show the tendency to walk upright through water, even if it is not strictly necessary. I guess they took this example a step further.

now some major speculation from my part.
i guess that the advantage of keeping your head above water must lie somewhere in risk reduction. Increased length increases your safety zone. It might also cost less energy (for a non-aquatic animal) to stand in water compared to swim in it.
but i don't really know.

The main problem is with dismissing this theory is that the evidence for the accepted theories isn't that great either. They do had the benefit of being published first and we all know how difficult it is to change an accepted dogma.



some comments on Frencheneesz then. I'm not going to bother to do them all, since it is not my frikking theory.

Originally posted by Frencheneesz
"easily accessible, reliable food source (coastal region)... "

easily accessible? in what way? Reliable food sources can be found anywhere that life grows. And it would be a bit tough to actually find easy food sources for an ape-like creature on the coast of the ocean. what would there be to eat? Clams are too hard (needs a bit of intelligence to actually use it efficiently), but perhaps. And there are fish, but no edible plants or large animals. Don't you think the land has quite enough resources for food. Look at the apes in the congo. Natural selection requires the non-reproduction of "less suited" animals, but apes that didn't look for food in the ocean would surely find food on land.


i think that the sea or a lake is quite a rich source of proteins. You might know that protein rich food is more nutritious as vegetation. Hence there could be some kind of advantage.


Originally posted by Frencheneesz
Everyone needs fat. Come on, humans and apes are not the only land animals that have fat in such quantities....
[/B]

the difference is that our fat is sub cutaneous, similar to aquatic animals. Unlike any other ape or monkey...or non-aquatic mammal (as far as i know)


Originally posted by Frencheneesz

"Voluntary Breath Control "
______________________

I think a much more feasible explanation is that we need to eat though our mouth. If we didn't have voluntary breathing control, we would all mostly choke to death on our food, not on water.
[/B]
except that most animals don't have this and still have to eat. Personally i think that this particular feature has something to do with the advent of speech and not the putative aquatic lifestyle.




Originally posted by Frencheneesz

Its great that you are thinking about new ideas, but you should not accept them without substantial evidence that is relevant. So far, even if this theory explained all those things you listed, you still have not given us a good advantage for living aquatically. [/B]

of course, as long as we keep in mind that there is no real definite evidence for the other theories either. Hence it seems it bit silly to trash this one for no good reason.

and of course spookz gave us a quite a good view on the current ideas and i feel that I now might have undone his good work by posting my petty nonsense.

This wet scenario requires no great evolutionary steps. Forest-dwelling herbivores like capybaras, tapirs or pygmy hippos are partially adapted to the water collections in the tropical or subtropical rain or gallery or mangrove forests, but remain four-legged. In these shallow waters, primates - which, because of their arboreal history, have very mobile joints and a tendency to body erectness - easily adopt a bipedal stance and gait. Lowland gorillas go wading on their hind legs through swamps to get edible sedges and AHV (Chadwik, 1995; Doran & McNeilage, 1997). Proboscis monkeys Nasalis larvatus cross stretches of water on two legs to reach other mangrove trees (Morgan, 1997; Ellis, 1991). Japanese monkeys Macaca fuscata on islands walk bipedally into the sea (e.g. Morgan, 1997).

In mangrove swamps, lower tree parts are occupied with bivalves, which are exposed at low tide (Fernandes, 1991). No doubt, inventive inhabitants of such places began to exploit these rich food sources, just as capuchin monkeys do, who feed on crustaceans and oysters. These relatively large-brained primates even use oyster shells to crack other oysters when no stones are available (Fernandes, 1991). Probably, human ancestors, who already cracked hard-shelled nuts and fruits with stones, used pebbles as tools, at first for opening shellfish and later for processing other food sources like carcasses of hippopotamuses (e.g. Bunn, 1981). Once they mastered how to cut through skins with sharp stones or to use stone tools for processing wood, they would have seen new niches open to them, encouraging them to invade the inland along the rivers.

Physiological data make it very probable that the phase of partial shellfish collection at one time included frequent diving (Schagatay, 1996). Today, human populations all over the world still collect shellfish or seaweed through diving. It could perhaps explain some human parallelisms with sea-mammals, according to the ideas of the so-called aquatic hypothesis of human evolution (Westenhöfer, 1924, 1942; Hardy, 1960; Morgan, 1982, 1990, 1997).

Among these adaptations, those for diving and breath-holding (Schagatay, 1996), in combination with an older sound production as in many arboreal animals like gibbons (Darwin, 1871), could have led the basis for the voluntary and articulate sound production of human speech (Verhaegen, 1997). In this respect, Derek Ellis (personal communication) remarks ëhow well sound travels over water, compared to being muffled in forests, and even compared to grassland. Foraging beach and lagoon apes could separate quite widely and still remain in contact by vocalisingí.

Although both Australopithecus and Homo species seem to have dwelt at the edge between land and water, the differences in paleo-milieu, dentition, tool use and brain size suggest that both had different lifestyles. Nevertheless, there is a completely natural sequence of small behavioural innovations that could lead from early australopithecines to modern humans (points 2 to 5 are seen in chimps or gorillas, see Yamakoshi, 1998; Chadwik, 1995; Ellis, 1991; Nishida, 1980; Golding, 1972).

* frugi- and herbivory in tropical forests (all hominoids),
* using stones to crack hard-shelled fruits and nuts,
* frugi- and herbivory also in forest clearings,
* plus ěshortî-legged bipedal wading in shallow waters,
* plus more frequent surface-swimming,
* wading and swimming also in mangrove forests,
* plus feeding on bivalves growing on lower tree parts,
* using shells or stones to crush shellfish,
* using stone tools for various purposes,
* colonising the seashores and rivers as omnivores,
* re-invasion of the land along the rivers,
* long-legged bipedalism on land.

Conclusion
The combination of comparative, physiological and paleo-environmental data makes a savanna evolution improbable, but does not exclude a temporary evolution of human ancestors and relatives at the edge between land and water. Many human features cannot be explained by a history of tree or forest dwelling alone, but find convergences in primates that live in mangrove areas, such as proboscis monkeys and some tufted capuchins. The paleo-environmental and dental data suggest a gradual evolution, in strongly overlapping phases, from frugi- and herbivores in gallery or tropical or mangrove forests to ěshortî-legged bipedal waders in forest clearings or mangrove swamps, to omnivores and partial shellfish feeders along seacoasts and rivers, and finally to long-legged bipedalists on land._(Marc Verhaegen)


Hominid lifestyle and diet reconsidered (http://www.riverapes.com/AAH/MV/HEsept.98.doc)

river apes (http://www.riverapes.com/)

Spookz

Forest-dwelling herbivores like capybaras, tapirs or pygmy hippos are partially adapted to the water collections in the tropical or subtropical rain or gallery or mangrove forests, but remain four-legged

Of course, they are plainly terrestrial, as are we.

Physiological data make it very probable that the phase of partial shellfish collection at one time included frequent diving (Schagatay, 1996). Today, human populations all over the world still collect shellfish or seaweed through diving. It could perhaps explain some human parallelisms with sea-mammals, according to the ideas of the so-called aquatic hypothesis of human evolution

Nonsense. Throw a dogs favorite chew toy in the deep end of a swimming pool and watch the dog dive down to the bottom and retrieve the toy. According to the theory, the dog must also have evolved with sea-mammals.

The combination of comparative, physiological and paleo-environmental data makes a savanna evolution improbable, but does not exclude a temporary evolution of human ancestors and relatives at the edge between land and water.

I'm inclined to consider the Savannah theory has more validity than ATT, but that doesn't mean I think Savannah is correct either.

The paleo-environmental and dental data suggest a gradual evolution, in strongly overlapping phases, from frugi- and herbivores in gallery or tropical or mangrove forests to ěshortî-legged bipedal waders in forest clearings or mangrove swamps, to omnivores and partial shellfish feeders along seacoasts and rivers, and finally to long-legged bipedalists on land.

So, why are there no other semi-aquatic animals that developed bi-pedalism ?

Spurious

The main problem is with dismissing this theory is that the evidence for the accepted theories isn't that great either. They do had the benefit of being published first and we all know how difficult it is to change an accepted dogma.

The Aqua-ape theory is fanciful and fun, and there's just enough "sciency" stuff to wow any layperson. But the underlying premises are ALL refutable and the logic fallacious. THAT is why it is dismissed as whimsical by all reputable paleoanthropologists.

If you think AAT is serious science, you are kidding yourself. It is not even mentioned, except for the purpose of refutation, in mainstream peer-reviewed literature.


btw - The main proponent of ATT, Elaine Morgan, was a television screenwriter with no post-graduate education.

q

the verhagen and lewis quotes were mainly to give an idea on the conditions that existed at the time primates were supposedly aquatic. from what i understand it was a period of increasing temps and shrinking woodlands.

also take note aat is getting watered down from the homo's being water dwellers to simple waders. eg the hybrid theory......semi-aquatic..

the savanna scenario seem less plausible than a wetter one for the simple reason that there would be more food available in the latter. but then again why has there to be a choice in habitat? perhaps both were populated?

the main controversy is adaptations and i thought that had been resolved.

shit from the straight dope

". . . [T]he exceptional ability of Man to swim . . ." Not very exceptional. Hardy admits "many" animals can swim on the surface. In fact, almost all terrestrial mammals can. With very few exceptions, adult mammals, when introduced to the water for the first time, can swim without any previous training. This is largely because they tend to float horizontally and are able to keep their nostrils above water. Apes and humans, on the other hand, tend to float vertically with their nostrils submerged. Humans (and at least some apes) can learn to swim, but it doesn't come naturally. Based on this point alone, hominoids would appear to be among the least likely mammals to return to the water.

". . . I have been told that babies put into water before they have learnt to walk will, in fact, go through the motions of swimming at once . . . " Partly true, but misleading. Babies, placed face down in the water, can hold their breath and rather inefficiently propel themselves through the water. Their motions are as much like crawling as they are like swimming. Babies cannot, however, lift their nostrils above water unassisted to breathe, which would seem to make their much-vaunted "swimming" ability worthless. Nor are human infants unique in being able to propel themselves through the water; the young of many, probably most, terrestrial mammal species can do the same.

"Does the idea perhaps explain the satisfaction that so many people feel in going to the seaside, in bathing, and in indulging in various forms of aquatic sport?" Uncertain, probably unverifiable, and more than a little silly. One of my neighbors had a trampoline in his back yard instead of a pool. Was he trying to recapture the days when our ancestors' bottoms were made out of springs? Are we Tiggers or are we men?

"Whilst not invariably so, the loss of hair is a characteristic of a number of aquatic mammals . . ." True, if you take "a number" to mean "a small number." Fur or hair is no great hindrance underwater. Fur seals, otters, beavers, and polar bears haven't lost theirs and they swim better than we do. Only some aquatic mammals have lost all or most of their hair, and they are almost invariably very large species weighing a ton or more, whose ancestors have been living in the water for tens of millions of years. Contrary to popular thought, fur remains an effective insulator even in water, because it traps a layer of stagnant water (or in the case of the sea otter, air) next to the skin. Further, our ape relatives generally have sparse hair, though not quite as sparse as ours. What do AAH supporters make of relatively hairless terrestrial species, such as the elephant, rhinoceros, and pig? They postulate an aquatic past for them as well. It just goes to show that you can explain away any inconvenient fact if you try hard enough. The real reason these species, including humans, lost their hair was to dissipate heat faster. If anything, we lose heat too fast when we're in the water (even tropical water), which should have made us retain our fur if we were really aquatic.

"All the curves of the human body have the beauty of a well-designed boat. Man is indeed streamlined." There's a big brown stain on this page of my copy of Morgan's book because when I first read this, I laughed out loud with a mouth full of coffee. Truly aquatic animals are shaped a lot like torpedoes. Let me know the next time you see a torpedo with long flowing hair, a slender neck, rounded shoulders, and enormous knockers. See if you can get her number for me first.

"The presence of . . . subcutaneous fat is a characteristic that distinguishes Man from the other primates." It is true that many aquatic animals have a thick layer of subcutaneous fat, but not, as Hardy supposed, for insulation. Their subcutaneous fat is mostly for streamlining and energy storage. Fat is a much poorer insulator than it is popularly thought to be, and poorer than fur even underwater. Of course sedentary western humans tend to be fat, but they are not a fair representation of humans. Even so, it must be admitted that the human species, even hunter-gatherers, are probably quite fat compared to most other terrestrial species. Most likely this is due to self-domestication. Animals who no longer need to fear predators, including man and his domestic animals, have become much fatter than their wild relatives. The same is true of hedgehogs, whose natural protection renders running away unnecessary. Is the distribution of subcutaneous fat in humans somehow exceptional? Not at all. Sedentary zoo apes on a high-calorie diet accumulate subcutaneous fat stores in exactly the same places we do. What is exceptional is the difference between human and aquatic subcutaneous fat. Truly aquatic animals have thicker layers of fat surrounding the whole body. In humans, the fat layer is thinner and, on parts of the body, non-existent.

"It seems likely to me that Man first learnt to stand erect in the water . . ." The idea here is that a primate tends to stand erect when wading in water, if it's deep enough. That's true, but it's not the whole story. Gorillas, bonobos, and chimpanzees all stand and walk on two legs occasionally when on dry ground. Their normal means of locomotion is knuckle-walking (i.e., walking on all fours with the knuckles of the hands on the ground rather than the palms). But the interesting part is the other apes: the orangutans and gibbons. Their normal means of locomotion is brachiating (swinging from branches). On those rare occasions when brachiators come down to the ground, they usually walk on two legs, like humans. There is a growing school of thought that the last common ancestor of humans and chimps was a brachiator and not a knuckle-walker as had been previously believed. This would require that knuckle-walking evolved twice (in gorillas and chimps) rather than once, an idea that not all experts accept. A fossil species called Oreopithecus ("swamp ape," not "creme-filled chocolate cookie ape") is cited by AAH supporters as an example of a primate that learned to walk upright by first wading in swamps. It is much more likely that Oreopithecus was a brachiator than a wader. It's worth noting that no aquatic species regularly walks on two legs when on land.

"Where are the fossil remains that linked the Hominidae with their more ape-like ancestors? . . . It is in the gap of some ten million years, or more, between Proconsul and Australopithecus that I suppose Man to have been cradled in the sea." It wasn't until recently that we knew how wrong Hardy was on this point. Since he wrote it in 1960, the gaps have been progressively filled in, most famously by Lucy in the 1970s. In late 2000 a specimen dubbed Millennium Man (Orriorin tugenensis) was discovered in Africa. It must have lived very close to the time when humans and chimpanzees diverged and fills in another important gap. It appears to have already developed upright walking, but also retained some climbing adaptations. The fossil gaps up to the last common ancestor of chimps and humans are now measured in hundreds of thousands of years rather than Hardy's tens of millions. Oddly enough, Morgan has used this point as an argument in favor of the AAH. She suggests that the gaps are so short that only something as revolutionary as an aquatic stage could account for the changes. OK, but when two contrary facts are both used in support of a hypothesis, alarms go off. Besides, the evolution of human features displayed by the fossils appears to be reasonably gradual, not abrupt. None of the fossils suggest an aquatic lifestyle.

fairly satisfactory, wouldnt you say q?
just for the fun of it i am gonna try hook eskimos and pacific islanders to one or more variations of aat. oh.. oh... how about a marsh dwelling amazonian aquatic indian?

:D

is diving and catching fish part of a dogs natural behaviour. (wild dogs that is)
i am sure wolves fish (dependant on habitat of course)

So, why are there no other semi-aquatic animals that developed bi-pedalism ?

dunno, maybe different species have different evolutionary lines?

aat was hardy's theory (marine biologist) morgan merely milked it for all it was worth

Spurious

The main problem is with dismissing this theory is that the evidence for the accepted theories isn't that great either. They do had the benefit of being published first and we all know how difficult it is to change an accepted dogma.

The Aqua-ape theory is fanciful and fun, and there's just enough "sciency" stuff to wow any layperson. But the underlying premises are ALL refutable and the logic fallacious. THAT is why it is dismissed as whimsical by all reputable paleoanthropologists.

If you think AAT is serious science, you are kidding yourself. It is not even mentioned, except for the purpose of refutation, in mainstream peer-reviewed literature.


btw - The main proponent of ATT, Elaine Morgan, was a television screenwriter with no post-graduate education. [/B]

could you sum up the evidence that supports the other side of the story?
I can't...maybe that is why i'm not particulary wowed by any of these theories.

i'm assuming there isn't that many evidence, since lifestyles don't fossilize that well and the fossil record of human evolution is quite sparse....but at the same time i must admit that i never bothered to look into this matter.

in conclusion: I'm just saying that the evidence for both camps is quite meager, hence i'm not willing walk on fire for any of these theories. On the other hand a modified AAT could be quite elegant and I like elegant theories. It's not illegal to be creative in science.

the truth lies always in the middle

edit: it seems that the debate is not over yet in science...a search on ISI reveals still articles.
latest:
Aquarboreal ancestors?
Verhaegen M, Puech PF, Munro S
TRENDS IN ECOLOGY & EVOLUTION
17 (5): 212-217 MAY 2002
Abstract:
According to biomolecular data, the great apes split into Asian pongids (orang-utan) and African hominids (gorillas, chimpanzees and humans) 18-12 million years ago (Mya) and hominids split into gorillas and humans-chimpanzees 10-6 Mya. Fossils with pongid features appear in Eurasia after c. 15 Mya, and fossils with hominid features appear in Africa after c. 10 Mya. Instead of the traditional savannah- dwelling hypothesis, we argue that a combination of fossil (including the newly discovered Orrotin, Ardipithecus and Kenyanthropus hominids) and comparative data now provides evidence showing that: (1) the earliest hominids waded and climbed in swampy or coastal forests in Africa-Arabia and fed partly on hard-shelled fruits and molluscs; (2) their australopith descendants in Africa had a comparable locomotion but generally preferred a diet including wetland plants; and (3) the Homo descendants migrated to or remained near the Indian Ocean coasts, lost most climbing abilities, and exploited waterside resources.

didn't bother to read it...but apparently not everybody in science thinks it is completely crackpot as some people suggest...
unless these authors are also crackpots...i know for a fact that this is not uncommon in science.

Spookz

fairly satisfactory, wouldnt you say q?

Very good! Many of the claims made by proponents of AAT can easily be shown to be false. Here's another excellent critique:

http://biology.uindy.edu/Biol345/ARTICLES/umbrellas.htm

aat was hardy's theory (marine biologist) morgan merely milked it for all it was worth

Prior to Alister Hardy, a pathologist, Max Westenhofer included a chapter in his book Der Eigenweg des Menschen on the underlying principles of AAT. And although Westenhofer was not a paleoanthropologist, he soon abandoned the theory. Since then, no publishing proponent of AAT has been taken seriously by scientists.

And of course, one should never take seriously half-baked theories from a television screenwriter (ie.Elaine Morgan.)

Spurious

could you sum up the evidence that supports the other side of the story?

Could you be more specific. AAT and Savannah for example are not the only competing theories. There are others as well, among them are:

"Regional Continuity" model, the "Multiregional Evolution" model and the "African Origin" model. The African Origin model has three competing subtheories:"Replacement", "Weak Garden of Eden" and "Multiple Dispersals".

And so on...

I'm just saying that the evidence for both camps is quite meager, hence i'm not willing walk on fire for any of these theories. On the other hand a modified AAT could be quite elegant and I like elegant theories. It's not illegal to be creative in science.

It should be noted that paleontologists completely ignore the AAT simply because all claims made by proponents of the theory are shown to be false. You'll also find that the AAT is only published in journals which are NOT peer reviewed; such as The New Scientist, for example.

didn't bother to read it...but apparently not everybody in science thinks it is completely crackpot as some people suggest...
unless these authors (Verhaegen M, Puech PF, Munro S) are also crackpots...i know for a fact that this is not uncommon in science.a

You got that right!

I think here's your guy!http://www.horror-wood.com/DIETZ1.jpg

Monkey:

"i think that the sea or a lake is quite a rich source of proteins. You might know that protein rich food is more nutritious as vegetation. Hence there could be some kind of advantage. "

I suppose, but thats a bit vauge, but what happened to that advantage to make people leave the water?

"the difference is that our fat is sub cutaneous, similar to aquatic animals. Unlike any other ape or monkey"

Could you explain "sub cutaneous"? As far as I know, our fat system is much the same as any other mamal.

"except that most animals don't have this and still have to eat."

Most Animals with lungs (all that I know of) have the ability, can you give me an example of an animal with lungs that doesn't have voluntary breathing control.

Sure sure, its not your theory. But the idea is a bit zanny don't you think? And the evidence isn't all that conclusive either. Why would we loose hair? Well, why does some cats have no fur? Its simply because we are different, and we happened to have good traits along with the weird no fur trait. Diversity will happen as long as the traits aren't harmful.

I think you may be remembering a hypothesis that I ran across five or ten years ago.

The idea was that when our ancestors climbed down out of the trees and left the ancestors of the chimpanzees up there, to become two distinct species, they did not hit the ground and start walking around. This would not have been easy because the ground was already well populated with both herbivores to compete for the food and carnivores to compete for our blood.

Suppose there was a lake nearby. Lung breathers rule in the water because we metabolize so much more oxygen than gill breathers, that's why the few species of mammals that have returned to the sea are so incredibly successful. As long as the lake wasn't home to any alligators, all we had to do was figure out how to catch fish or just scrape up and open the shellfish and life suddenly got real easy.

After commuting between the lake and the trees every day, we eventually became more confident on the land and population pressure motivated the more adventurous proto-hominids to try their luck on the savannah.

This theory will be mighty difficult to prove or refute, but the evidence is intriguing.

1. We are the only apes with those little webs between our fingers. Maybe they were once bigger webs.
2. We are the only apes with the right build and density to be even mediocre swimmers, much less the outstanding swimmers that we actually are.
3. A three dimensional universe spurs brain development. Again, just look at the cetaceans and pinnipeds. Many birds seem to be quite a bit brighter than mammals in similar ecological niches. Swinging through the trees certainly qualifies as a three dimensional environment and, sure enough, simians in aggregate are the most intelligent mammals. But how did we, who settled for a life in two dimensions, end up so much smarter than the guys who stayed up there? Perhaps by spending a few hundred thousand years moving about even more freely in the water?

I am sorry I came late at this topic, but better late than never.

Elaine Morgan was mentioned several times and I am not sure if anybody commented on her masterpiece DESCENT OF WOMAN.
In the book she brilliantly exposed aquatic theory explaining the origin of speech and other traits that makes us so much different from other apes. A million years in shallow waters made crucial difference. ;)

Originally posted by (Q)
didn't bother to read it...but apparently not everybody in science thinks it is completely crackpot as some people suggest...
unless these authors (Verhaegen M, Puech PF, Munro S) are also crackpots...i know for a fact that this is not uncommon in science.a
You got that right!

and:

It should be noted that paleontologists completely ignore the AAT simply because all claims made by proponents of the theory are shown to be false. You'll also find that the AAT is only published in journals which are NOT peer reviewed; such as The New Scientist, for example.


Trends in Ecology & Evolution
looked up the journal...it had an impact factor of 10...that is not that bad actually...My last article only went to a journal with impact factor 8. Most researchers are even happy with a lot less.

I did notice that the article was under the opinion sector and i do not know if it has been peer reviewed, but i really doubt it if they would publish something like this if it was really unscientific and crackpotty...
The fact that I found other articles supporting this theory (or better put, parts of this theory) gives us some indication that we might assume that the entire matter is not as unscientific as some people suggested.


Originally posted by (Q)
Spookz


could you sum up the evidence that supports the other side of the story?

Could you be more specific. AAT and Savannah for example are not the only competing theories. There are others as well, among them are:

"Regional Continuity" model, the "Multiregional Evolution" model and the "African Origin" model. The African Origin model has three competing subtheories:"Replacement", "Weak Garden of Eden" and "Multiple Dispersals".

And so on...


isn't that interesting...so many theories...the presence of many theories in science usually indicates a high degree of uncertainty.

My conclusion would therefore still stand. This matter is far from settled and there is no conclusive evidence for any of these theories. Which one do you like personally???

Originally posted by Frencheneesz
Monkey:

"i think that the sea or a lake is quite a rich source of proteins. You might know that protein rich food is more nutritious as vegetation. Hence there could be some kind of advantage. "

I suppose, but thats a bit vauge, but what happened to that advantage to make people leave the water?


i guess that is not clear, but let's recap what the thought is about a semi-aquatic life style.

during a certain period of the evolution of hominids a species chose (for some reason) to adopt a semi-aquatic lifestyle. This could have been a cultural event. We know for instance that chimpanzees groups all have different habits which they pass on from generation to generation. Maybe one ancestor group had the habit of spending lots of fouraging time near water. Because of this there was a selective pressure for phenotypic characteristics that suited this environment. Maybe these particular hominids were succesful in a certain area. Maybe this ensured that there was a continued selective pressure for a prolonged period of geological time. maybe this was the time when earlier mentioned features developed.
Then this era ended. These hominids were successful and started spreading to different environments. For what reason? maybe they could outcompete other species in environments in which they couldn't before. And then they spread and the selective pressure for the pure aquatic features disappeared.


Originally posted by Frencheneesz


"the difference is that our fat is sub cutaneous, similar to aquatic animals. Unlike any other ape or monkey"

Could you explain "sub cutaneous"? As far as I know, our fat system is much the same as any other mamal.


It has been a long time ago, so I might make a few mistakes in my explanation. Most animals tend to store excess fat in the abdomen. Hence a fat gorilla still has lean looking arms. We store a lot of fat under the skin (hence) the fat arms of a fat person. Some people attribute this to an aquatic adaptation...but then again, pigs store quite a lot of fat here and are not aquatic.

but in the end you might be able to discredit each feature, because other terrestial animals have similar features, but i guess what lots of people found intriguing is that humans have many of these features combined in one species.

quote:



Originally posted by Frencheneesz

"Voluntary Breath Control "
______________________

I think a much more feasible explanation is that we need to eat though our mouth. If we didn't have voluntary breathing control, we would all mostly choke to death on our food, not on water.
[/B]

We can for instance choose to breath with our mouth or our nose. A dog would always breath in through the nose and out through the mouth. I don't know in how far other animals can choose not to breath. I have seen dogs pick up things from under water, so they must be capable to hold their breath. Maybe it is a degree question. To what degree do you have volentary breath control. But personally I don't think that this is one of the stronger points...

Spurious

I did notice that the article was under the opinion sector and i do not know if it has been peer reviewed, but i really doubt it if they would publish something like this if it was really unscientific and crackpotty...

You will not find the AAT in any peer reviewed journals except when used for refutation. The theory has been shown to be false, therefore it is ignored, just like any other crackpot theories.

The fact that I found other articles supporting this theory (or better put, parts of this theory) gives us some indication that we might assume that the entire matter is not as unscientific as some people suggested.

The AAT has been around for almost 75 years - it is not a starter hypothesis. In any case, a number of crackpots have leagues of followers who also write articles supporting their hair-brained theories, scientific or otherwise. That doesn't make the theories any more valid or credible especially when the theory has already been proven false, as is the case with AAT.

isn't that interesting...so many theories...the presence of many theories in science usually indicates a high degree of uncertainty.

Why would you say that ? A sceptic would see that as a high degree of crackpots trying to undermine accepted theories with their own nonsense.

My conclusion would therefore still stand. This matter is far from settled and there is no conclusive evidence for any of these theories.

You may conclude whatever you wish. But the AAT has been settled. Elaine Morgan, Marc Verhaegen, et al. are crackpots every much as people like Nancy Leider, Tom Bearden, Richard Hoagland, etc.

Did I also mention that Elaine Morgan is not a biologist, she is a television screenwriter.

Here's something to think about. When the semi-aquatic population returns to land, by what Darwinian mechanism are they able to out-compete the population that never became semi-aquatic in the first place?

This terrestrial population had allegedly 1.5 million more years on land to become ultra-specialized at terrestrial living.

To reason that the semi-aquatic population, which just allegedly spent 1.5 million years specializing in semi-aquatic living could out-compete the same ancestral population that spent the same amount of time further specializing in terrestrial living defies any Darwinian explanation.

I looked into the article I mentioned before. It is not unscientific in nature (yes, i have reviewed papers before, and rejected some because they were not up to standard. I know the business).

they seem to base their speculations on 4 different sets of evidence: 1. comparisons of postcranial skeletons, 2. tooth enamel microwear, 3. strontium:calcium ratios, 4. isotopic evidence. You might not agree with their conclusions based on this evidence, but that doesn't mean it is unscientific. I'm not really totally convinced after reading the article (although they make some interesting analogies), but i doubt that I would be totally convinced reading articles about the other theories, because in general we just have a lack of evidence.

I find it really strange that the opinions are so polarized on this matter in this forum when there is clearly no definitive evidence for any of these theories. If you think otherwise then please endulge me and point me towards it.

Q:
and no...the theory has not been proven to be false. Some people think it is not true...it is not the same.

++Here's something to think about. When the semi-aquatic population returns to land, by what Darwinian mechanism are they able to out-compete the population that never became semi-aquatic in the first place? +++

because adaptations to the 'aquaboreal' lifestyle gave them advantages in the end.... Adaptations that are evolved for one purpose sometimes turn out to be useful for other purposes, or have multipurpose to start with. Sometime certain environments just accelerate the evolution of certain structures. It's all hard to predict, and even in hindsight it is difficult to guess which selective pressure caused which feature.

+++You will not find the AAT in any peer reviewed journals except when used for refutation+++

except that this one was in a peer reviewed journal and I found other articles supporting aqua-arboreal ideas in peer reviewed journals.
I think we settled now the question if ATT is represented in peer review articles or not. It is.

Much of the confusion between the orthodox and the alternative view of human evolution seems to be caused by deficient definitions of 'terrestrial' and 'aquatic'. After all, what is the difference between 'semi-terrestrial' and 'semi-aquatic'? If 'aquatic' only means 'marine', or if it means 'fully aquatic' as in sirenians (dugongs and manatees) and cetaceans (whales, porpoises, dolphins), these views are improbable in our opinion (e.g., Bender et al., 1997). And if 'terrestrial', as opposed to 'aquatic', includes 'arboreal', everybody agrees that humans display many 'terrestrial' features. No aquatic theorist doubts that many human characteristics are, at least partly, due to our arboreal inheritance, for instance, our tendency to truncal erectness, elongated limbs, mobile hands, large brain, and varied sound production (e.g., Verhaegen, 1993, 1997). Nevertheless, there can be no doubt that if 'terrestrial' only means 'savannah', this view is comparatively and physiologically impossible, since humans in almost every respect are very different from savannah-dwellers (e.g., Schmidt-Nielsen, 1979; Morgan, 1982, 1990, 1997; Verhaegen, 1991b, 1997).


characteristics of a savannah dweller

*relative independence of drinking-water and water-containing nourishment, high tolerance of dehydration and radiation heat, high diurnal body temperature and high daily temperature fluctuations, high renal concentration power, very large external ears, slender build, and running velocities of 30 miles per hour and more.
*Savannah mammals are never plantigrade like bears, eared seals or African hominoids.
*Most of them do not have dextrous hands like racoons, many otters and primates.
*They never have abundant subcutaneous fat deposits, but protect themselves from the sun with short, light-reflecting fur (or with mud coverings in elephants or rhinoceroses).
*Their vocalisations are less varied than those of dolphins, otters or primates. *They never copulate face to face like some slow branch-hangers (sloths, pottos, orang-utans), marine mammals (cetaceans, sirenians) and humans. All have an excellent sense of smell, as opposed to many marine mammals and humans.
* Most of them grow up fast and reach adulthood in two or three years, unlike hominoids, walruses, cetaceans or sirenians.
*They can sustain body temperatures of more than 40°C (Grant's gazelle can maintain 46°C for many hours) and show temperature fluctuations of more than 6° between day and night.
*Their urine concentration can be twice that of humans.
*They can bear a dehydration of 20 per cent and more, whereas in humans a dehydration of more than 10 per cent is fatal without medical intervention. *They are very conservative with salt and water (many savannah mammals, even carnivores like the fennec fox, do not need drinking-water), and never sweat ten to fifteen litres a day as humans can do in hot environments (hunting-dogs and many other savannah-dwellers do not sweat at all). (Marc Verhaegen)

*There are two ways in which a new idea in science is rejected: one is by direct confrontation and attempts to refute it, the other is by turning a blind eye to it and hoping that it will simply go away (Tobias, 1998).

*In her talk earlier the day, Elaine Morgan tried to understand why the idea has been simply denied, instead of scientifically debated. She came to the conclusion that for a large part it may be simply because of her person. She doesn't have an academic degree and at the time she first developed further Alister Hardy's idea, she was a militant feminist. It must be said that at the symposium everyone was impressed by the rational arguments and evidence with which she addressed the different criticisms and how she admitted to have made claims which turned out later to be untenable.

*humans today are as aquatic as hominids have ever been and thus that if there has even been an aquatic ape, it would have to be ourselves.(langdon)

Spurious

I find it really strange that the opinions are so polarized on this matter in this forum when there is clearly no definitive evidence for any of these theories. If you think otherwise then please endulge me and point me towards it.

AAT is based entirely on false "facts." The arguments put forth by the proponents of AAT (Elaine Morgan) are filled with examples of ad hominem, ad hoc, Strawman, Irrelevant Conclusion, Fallacy of Exclusion, and Special Pleading.

The theory (or more precisely, hypothesis) is internally inconsistent - it is not only contradicted by facts, but by its own claims.

and no...the theory has not been proven to be false. Some people think it is not true...it is not the same.

The central idea of evolution is phylogeny, which places the AAT outside of all evolutionary theories to date. One simply has to understand evolution to refute the claims of AAT proponents.

because adaptations to the 'aquaboreal' lifestyle gave them advantages in the end.... Adaptations that are evolved for one purpose sometimes turn out to be useful for other purposes, or have multipurpose to start with.

Come now, you can't be serious. You're actually claiming that a group of fat, sweaty, naked aqua apes outcompeted their terrestrially adapted cousins ? Look back and you'll see that the AAT proponents argue that these adaptations (fat,sweaty,naked) make Homosapiens LESS able to compete on land, and that is why they are *proof* that our ancestors are semi-aquatic.

except that this one was in a peer reviewed journal and I found other articles supporting aqua-arboreal ideas in peer reviewed journals.

Then you probably also know that the AAT (more precisely AAH) is used in undergraduate courses as a case study.

I think we settled now the question if ATT is represented in peer review articles or not. It is.

Citation please.

AAH is not good science. Whether the proponents of AAH are trying to deceive laymen with their pseudo-babble or they simply have done very bad research - irregardless, the AAH is clearly in the realm of pseudoscience.

Q...i'm just going to go through a few essential points and not answer every single point.

Q..I suspect you are just being malicious here...there have been given several references already...i'm not going to repeat them over and over and you may want to use a scientific search engine yourself if you want more.

the aquaarboreal theory is not based on false facts, but based on the same facts as the other theories are based on...if you have actually read the article you might have seen that Verhaegen uses the normal evidence that is around, but interprets it differently.

++The central idea of evolution is phylogeny.+++

The central idea of modern evolution is natural selection. There were already evolutionary theories around before Darwin. What Darwin did was to introduce natural selection as a mechanism. And that is what is so attractive about it. See for instance 'the growth of biological thought', Ernst Mayer; Part 2 chapter 8 'Evolution before Darwin.'

I am under the impression that you might have a view on evolution that is not entirely realistic. There is no reason to assume that adaptations developed for an aqua-arboreal lifestyle could actually turn out to be advantageous in other environments. One of the classic mechanisms of speciation is island-isolation. A certain population of a species is cut of from the parent species (this could be an island, but often the island is merely an analogy). They encounter a different microclimate in this 'island', they evolve into a different species. Later the barrier disappears between parent and modified species, but still the modified species manages to obtain a foodhold in the original terriory of the mother species, or even outcompete them.
As you can see there is nothing strange about the idea that a hominid species partially adapted to an aqua-arboreal lifestyle could venture out of its original environment and even outcompete your classic terrestial species. it could have been a classic example of island speciation.

Therefore, theoretically, it is a classic story of evolution, not a story that will not fit with evolution. Although we might personally disagree with this particular theory if you think that the speculation is not warranted and you prefer other speculation

where you go wrong is that you take the idea too far. When you think of an aquatic ape, you see some kind of dolphin human...what you should be thinking is that humans have evolved a few features that could be explained by a lifestyle that involved spending a large amount of time near/in water. In this envirnoment, these feature could have been beneficial. These features could also have been beneficial in other envirnoments. Humans have never been fully aquatic.


I have to conclude so far (as a biologist), that ATT is scientific. I also conclude that the evidence for it is flimsy and that gives us reason to doubt it. I also concluded that the evidence for the other theories is equally flimsy...therefore you might doubt them too.

Spurious

Q..I suspect you are just being malicious here...

What reason would I have for being malicious ? Simply because I understand why the AAH is bunk ?

if you have actually read the article you might have seen that Verhaegen uses the normal evidence that is around, but interprets it differently.

Interesting you would say that - from your point of view, I would respond that Verhaegen interprets the evidence incorrectly.

There were already evolutionary theories around before Darwin. What Darwin did was to introduce natural selection as a mechanism

Then if you understand Darwin's theories, you'll understand why AAH is nonsense.

I am under the impression that you might have a view on evolution that is not entirely realistic.

That is your opinion, and of course, I could say the same of you.

A certain population of a species is cut of from the parent species (this could be an island, but often the island is merely an analogy

Aside from the AAH, can you cite one single species which would qualify this claim with the understanding that your reasoning is parallel to that of the AAH ?

As you can see there is nothing strange about the idea that a hominid species partially adapted to an aqua-arboreal lifestyle could venture out of its original environment and even outcompete your classic terrestial species.

So, by your reasoning, if Homosapien ventured back to the sea and became a Merman/Mermaid, they would outcompete the terrestrial Homosapien upon returning to land ?

Although we might personally disagree with this particular theory if you think that the speculation is not warranted and you prefer other speculation

I try not to speculate against hard evidence as anything but what the evidence suggests. One must keep it simple.

When you think of an aquatic ape, you see some kind of dolphin human..

I think about aquatic apes exactly the way in which AAH proponents have hypothesized.

what you should be thinking is that humans have evolved a few features that could be explained by a lifestyle that involved spending a large amount of time near/in water

Spending time IN water is a lot different than spending time NEAR water.

I have to conclude so far (as a biologist), that ATT is scientific. I also conclude that the evidence for it is flimsy and that gives us reason to doubt it.

I don't think that AAT/AAH is good science because there is no evidence to suggest the hypothesis is consistent with accepted theory or even consistent with its own claims.

I also concluded that the evidence for the other theories is equally flimsy...therefore you might doubt them too.

Darwin's theories imo, are not flimsy. They are good theories which abound in good evidence. What is it you doubt about them ?

Darwin was wrong, in some aspects of his theory's. Not all of it is rubish but the greater part of it is, this is common knowlegde I thought? No?

NO!

q leans towards the fruitarian evolution theory.

:D

:D

fruitarian evolution theory

You mean this fruity theory:

http://www.beyondveg.com/cat/fruit-dreams/index.shtml

Of course Darwin was wrong: his pangenesis theory as a theory of heredity was completely wrong. Because a migration of hereditary material from all parts of the body to the sexual organs and the subsequent inheritance to the offspring, was already refuted during Darwin's lifetime. Darwin was also wrong to believe that acquired characters, for example changes in organs caused by use and disuse, are heritable (Lamarckism) (1, 10).

How does this affect his theory of evolution? The Common-descent-of-life part of evolution does not depend on a correct theory of heredity. Common descent was quickly accepted in Darwin's time. However the success of natural selection as the main causal factor in evolution depended substantially on a adequate theory of heredity.

And on evidence. Darwin's contemporaries were slow to accept natural selection. For good reasons? Now we have a 'correct' theory of genetics, Lamarckism is rejected, genetics is integrated in evolutionary theory, and natural selection is accepted as an important factor in evolution. The historical question whether Darwin's theories were accepted at the time for good reasons is of course unanswered by the current status of genetics.

it's still an interesting question. A more interesting and urgent question is: are there good reasons to accept current neo-Darwinism? It's the same question but now applied to the modern Synthetic theory of Evolution. What is true of all criticisms? Do the critics still have some good points? Is current neo-Darwinism well supported by an adequate theory of natural selection and genetics? Do we understand organisms in enough detail to claim that we understand how new species evolved?

In my opinion it's not merely the species that evolve out of strings of DNA, but it's also the surroundings that transform life itself and heavely influence transformation and evolution.

fukushi

would you have any opinons on epigenetics? (http://www.sciencemag.org/feature/plus/sfg/resources/res_epigenetics.shtml) science? junk science?

Fukushi

You forgot to provide the link to the site in which you copied/pasted your post. ;)

Here you go:

http://home.planet.nl/~gkorthof/korthof.htm

If you take out the effort to search and find this link, you certainly should read this shit, before you proved yourself wrong.

then you should have thought about this statement (that Darwin's theory has no flaws) a little longer before you spawned it.

Now, I don't care about copy/pasting normally, but if I do, it means that I agree with something and that I couldn't have put it better. I wasn't trying to make it sound like I wrote this shit, did I? I'm sorry guys:rolleyes: but point is:
(and this is my opinion) That Darwins theory about (especially that one) survival of the fittest, is utterly crap and BS. why? need I to explane why? okay here I go:

I'm mad at how these theory's are pulled from their original idear and being molded into whatever's applicable. In this way I've seen (for expl) faschist-neo-nazi-skinheads bashing in other people's head,...nice old Darwin provided them the moral and philosophical grounds to inflict their damage onto others.

How about that example, does it strike some sound, does it?
I know it's an example out of the extreme, but that's the point.

Fukushi

I wasn't trying to make it sound like I wrote this shit, did I?

Of course not - besides, your critique was far superior. I particularly like your formal evidence to support your interpretation of "survival of the fittest:"


I've seen faschist-neo-nazi-skinheads bashing in other people's head

Hey... I'm convinced. :D

:D

Establishing the Link

McClintock's early work was more then enough to make her famous. By the 1920s, the idea that genes were located on chromosomes was clearly established, but no one had yet been able to connect a specific chromosome with the groups of genes that geneticists called "linkage groups." McClintock took the 10 linkage groups of maize and gradually connected each one with a specific chromosome. Her microscopic observations of the landmarks on each chromosome were so exact that she was able to observe crossover (recombination events) through the microscope, and then show that they corresponded precisely to genetic recombination events in the next generation of corn.

This was fundamental work, responsible for establishing one of the great cornerstones of modern genetics, namely, the idea that genes have fixed positions on chromosomes. McClintock continued her research work at several institutions, including the University of Missouri and in 1942 took a position at the Cold Spring Harbor Laboratory on Long Island, New York. In 1944 she was elected to the National Academy of Sciences, and in the same year was elected as President of the Genetics Society of America, the first woman to hold the post. One might have forgiven her if she had decided to rest on her laurels. However, her most remarkable work was yet to come.

The First Clue:

It's particularly ironic that McClintock, having helped to establish the location of genes on chromosomes as orthodoxy, was soon to upset the applecart. But it's also characteristic of her style of work.

In her first two years at Cold Spring Harbor, she noticed some unusual characteristics in a strain of corn. The plants showed streaks and spots of color, an indication that mutations had taken place in the developing body of the plant. These plants, interestingly, contained a broken chromosome #9. McClintock immediately noticed that these patches were arranged in a way suggesting that the rate of mutation was constant for each plant. In a sense, something must be "regulating" the rate of mutation of the pigment genes.

In a few of these plants, she noticed another interesting sight. Every now and then, small portions of a plant would show greatly increased or greatly decreased rates of mutation. McClintock concluded that these sectors must result from the progeny of a single cell in which the gene regulating the rate of mutations had itself changed. She tentatively concluded that this unusual system must have two elements: first, an element that actually caused the mutations, and second, an additional element that controlled the activity of the first. As usual, she was right on the mark.

McClintock called the element that actually caused the mutations the Ds (dissociator), and the controlling element the Ac (activator). By careful observation she discovered that the Ds element was on the short arm of chromosome #9 (right where the chromosome breaks had occurred) and the Ac was far away, on the long arm of chromosome 9. Those observations, in and of themselves, were interesting, but the most important finding was the fact that these elements sometimes appeared at other locations on the chromosome.

Transposition:

By 1951, McClintock had clear evidence that Ac and Ds could change their positions on the chromosome. She coined the term "transposition" to refer to the movement of genetic elements from one position to another, and she had developed convincing evidence that Ac controlled its own mobility within the genetic system. Quite simply, Ac could remove itself from one place on a chromosome and reinsert itself in a different place. It could move.

For the first time, McClintock had shown that genes did not necessarily occupy fixed positions on chromosomes. The significance of this was not lost on McClintock. Another scientist might have been careless enough to treat the Ac-Ds system as an "exception" to the normal pattern of development, but not McClintock. In fact, her papers indicate that she saw transposition as one of the key events behind development in the growth of large organisms. Some of the differences between individual cells and tissues in the embryo, she thought, might be due to genetic re-arrangements caused by transposition.

What did this mean for biology? Genetics had just established the central role of genes on chromosomes in passing the determinants of heredity from one generation to another. It had established the rules by which genetic material was sorted, arranged, and recombined, and was beginning to understand how genes were constructed in a chemical sense. There was even hope that the rules by which genes are expressed would soon become clear. To many scientists, it may have seemed that McClintock had clouded this emerging certainty by dropping the wild card of transposition on the table. Just as they were beginning to see genes as genuine entities, here was McClintock telling them that some genes could hop around from one position to another.

This last point was too much for her fellow geneticists, most of whom simply didn't see the maize results as very important. I should add a personal aside here. I read about McClintock's work as a undergraduate in my first genetics course in the late 1960s. The system of "transposable elements" in maize was presented as a very interesting, but very obscure, exception to the general rule that genes are fixed on chromosomes. McClintock's work was respected, but it did not affect biology as it should have. Not for more than 20 years.

Transposition Rediscovered:

Barbara McClintock not only had the insight to see the importance of her work, she also had the good fortune to live long enough to see the rest of the scientific community catch up to her. In 1956 she reported on a second system of transposable elements on maize, known as the suppressor-mutator system. This system involved a series of transposable elements that are often located near pigment genes, suppressing their function, and producing colorless (white) kernels of corn. When the transposable element moves, the pigment gene is reactivated, producing a reddish splotch of cells on the skin of the kernel. Only can look at a spotted kernel and almost "see" the transposable elements moving. Once again, it involved two genes, one of which controlled the movement of the other. The Ds-Ac system was not an isolated exception, at least not in maize.

If transposition had remained an interesting, obscure, minor exception we might not celebrate McClintock's work today. Little, by little, however, bits and pieces of transposition were spotted in other genetic systems. It became clear in the lacc operon that one gene could control the expression of another. Studies on bacterial viruses (bacteriophage) showed that genetic material could insert itself into a chromosome, and then remove itself. Finally, the elusive genes responsible for resistance to antibiotics in certain bacteria were shown to reside on movable genetic elements. Transposable elements, to use the language that McClintock had developed 20 years earlier. Today the study of transposable elements is a major subfield of genetics and molecular biology.

Genetic Identity. Are all cells the same?

What does all of this have to do with us, you might ask? Well, in a way, it reinforces the original point of this essay. Let's think of another one of those things that we learned about biology way back when. For example, the notion that every cell of the human body is genetically identical. This was almost an article of faith when I studied developmental biology. Liver cells, for example, have exactly the same genetic information as, say, muscle cells. The only differences between them are the chances that have been brought about by the processes of development, and these do not involve changes in genetic information. Right?

Wrong. And that's why McClintock's work is so important.

The notion that every cell in the body is genetically identical fails to solve a couple of important genetic problems. One of these is the problem of antibody production. Antibodies, as you know, and proteins produced by the immune system. The immune system is capable of producing an enormous variety of different antibodies when confronted by new antigens, and this is the key to the immune system's ability to fight off disease, even diseases to which it has never been exposed. The number of different antibody proteins which the human immune system can produce is estimated to range from 100,000 to 1,000,000. And there's the problem.

Antibodies are proteins. Proteins are produced from mRNAs, which are transcribed from genes. Therefore, a human cell must have at least 100,000 antibody genes. But that's impossible. If that were true, virtually the entire human genome would be taken up just with antibody genes, which is most definitely not the case. So what's going on? What's the solution? If genes were fixed on chromosomes, there would be no solution.

Antibodies -- Shuffling the Deck:

In 1976, perhaps thinking along the same lines as McClintock, Susumu Tonegawa, a Japanese researcher working at MIT, decided to test the idea that antibody genes occupy fixed positions. He compared the location of different parts of the antibody gene sequence in embryonic cells with the same parts in cells from an adult mouse. To his surprise, the two parts of the gene, which were together in the adult, were separated in the embryo. What was going on?

The explanation, as Tonegawa showed with a series of elegant experiments, is that the "mature" antibody gene of the adult does not exist in the embryo. Instead, embryonic cells contain hundreds of alternate antibody gene "parts," which must be moved together to assemble the mature, functional gene. And this is what accounts for the ability of the body to make so many different kinds of antibody proteins.

In each of the millions of cells of the immune system, bits and pieces are moved from place to place on chromosomes to assemble a functional gene. They key is that which bits and pieces are selected is random, so that each cell assembles a slightly different gene. In effect, in each cell the "deck" of antibody parts is "shuffled" in a different way. The result is that the millions of cells of the immune system contain millions of different antibody-producing genes, preparing the body to face virtually any antigen.

The system that drives this rearrangement does not, strictly speaking, involve transposable elements. However, it does involve the movement of gene sequences from one point on the chromosome to another, reinforcing the generality of McClintock's results on the movement of elements within the genome.


The Plastic Genome:

Susumu Tonegawa received the Nobel Prize for his work, which fundamentally altered our understanding of how the immune system develops. As important as his work was, however, the significance of McClintock's studies, which preceded his by 25 years cannot be overestimated. She had clearly broken the ground that enable other researcher, including Tonegawa, to think of genes as elements that could move and rearrange. The genome is plastic.

In 1983 Barbara McClintock received the Nobel Prize, fortunate as always to have lived long enough to see the importance of her work recognized by others. How important were her discoveries? Barbara McClintock is one of only two women ever to receive an unshared Nobel Prize in science. The other was Marie Curie. Curie's importance to physics is quite comparable to McClintock's importance to biology. When Barbara McClintock died in 1992, one of her obituaries suggested that she might well be ranked as the greatest figure in biology in the 20th century. I think that estimate is about right.


The Thing About Facts (Barbara McClintock and the Jumping Genes) (The Thing About Facts
(Barbara McClintock and the Jumping Genes))

In 1896, Baldwin proposed that the body cells themselves achieve a certain plasticity, allowing them to acclimatize to new conditions, and over time a kind of gradual adaptation takes place throughout the population, which eventually becomes instinct. Baldwinism does not cross the Weissman barrier, and is accepted by neoDarwinism as part of adaptationism. Dennett grudgingly finds it useful to append to his 'cranes' theory, because it does some slight explanatory work, while still conforming to dogma. 'The saving grace for the Baldwin effect' he says 'is that organisms pass on their particular capacity to acquire certain characteristics, rather than any of the characteristics they actually acquire.'

A New Factor in Evolution By J. Mark Baldwin (http://www.santafe.edu/sfi/publications/Bookinforev/baldwin.html)

SOCIAL HEREDITY AND ORGANIC EVOLUTION (http://spartan.ac.brocku.ca/~lward/baldwin/Baldwin_1899/Baldwin_1899_appA.html)

The Baldwin Effect: A Bibliography (http://www.cs.bath.ac.uk/~jjb/web/baldwin.html)

Facts

In the 1930's, heritable epigenetic effects due to the interaction of homologous alleles were described and designated paramutation, since Mendel's laws were violated.

Paramutagenic allele = an allele that will convert a paramutable allele to a paramutant allele.

Paramutable allele = an allele that can convert to a paramutant state.

Paramutant allele = an allele of lower function caused by paramutation, inherited somatically and germinally.

Paramutant alleles do not require the continued presence of the paramutagenic allele to maintain their state. They do, however, revert to the paramutable state with some frequency.

For the Rlocus of maize, the paramutant state is correlated with increased methylation of Rlocus DNA.

Transgenes will sometimes become silenced. Often, the silencing correlates with increased methylation of the transgenes.

Silencing by methylation resembles RIP'ing.

Not all gene silencing occurs by methylation coupled mechanisms. Some may be triggered by heterochromatization of the repeated gene. Others (Co-suppression) appear due to post-transcriptional events.

Interpretations

Induced changes in methylation status are metastably heritable and can affect gene expression.

Paramutation may be a manifestation of an important as yet undiscovered regulatory mechanism.

Paramutation (http://opbs.okstate.edu/~melcher/MG/MGW1/MG1383.html)

greek! (http://waksman.rutgers.edu/Waks/AnnualReport/MessingReport/MessingReport.html)

Genomic imprinting is a genetic mechanism which determines the expression or repression of genes according to parental origin. This modification of genetic material is reversible between generations i.e. epigenetic suggesting that the inactivation event is not a mutation.The phenomenon has been well studied in mice.

Evidence from human disease

Evidence supporting the existence of imprinting in humans has been obtained from the study of human chromosome deletion studies such as Prader-Willi and Angelman syndromes.

Myotonic muscular dystrophy (MMD) and Fragile X syndrome exhibit genetic anticipation, whereby the phenotype of the disorder becomes progressively more severe with each generation. Although the genes for these disorders contain unstable triplet repeats these diseases still fulfill the definition of genomic imprinting because each disease locus is affected differently upon passage through female versus male gametogenesis. Expansion of the triplet repeats leading to disease only occurs through female transmission.

In 10% of families with MMD, the disorder is more severe when maternally inherited.
Fragile X linked mental retardation is more common in later generations of an affected family.
Juvenile-onset Huntingtons disease is more common in offspring of affected fathers.

Other diseases affected by genomic imprinting includere congenital heart disease, neural tube defects and cerebellar ataxia

Cancer and genomic imprinting

In certain cancers i.e. Wilms' tumor, osteosarcoma, bilateral retinoblastoma and embryonal rhabdomyosarcoma, the origin of the tumor-suppressor gene remaining in the tumour appears to be invariably paternal. In the two-hit hypothesis of cancer, the first inactivation of a tumour-suppressor allele would occur through imprinting rather than mutation. Because the inactivation is not dependent on the tumour-suppressor allele but rather the genes responsible for the generation of the imprint, the inheritance of the tumour phenotype will not be linked to the tumour-suppressor locus. This is confirmed by studies of large families with Wilms' tumours and less convincingly with rhabdomyosarcoma.

Uniparental disomy

UPD is caused by meiotic non-disjunction followed by trisomy or monosomy rescue and is associated with advanced maternal age. Studies of the phenotypes associated with UPD have been used to determine an imprinting map.

UPD has been reported for 25 out of the 47 possibilities for entire chromosomes.
Assessment of whether the phenotypic consequences are due to imprinting is complicated by the affect of trisomy on the placenta or foetus or autosomal recessive disease due to homozygosity. If a consistent abnormal phenotype is present in different documented cases of UPD autosomal recessive disease can be excluded . Conversely, if a single case of UPD is associated with a normal phenotype this provides strong evidence of a lack of an imprinting effect for a particular chromosome.

Chromosomes associated with imprinting

15 maternal 20-25% PWS
15 paternal <5%AS
11 pat 20-25% BWS
7 mat short stature 4/30 patients with Russell-Silver syndrome
14 mat distinct phenotype

Other chromosomes which have shown possible genomic imprinting effects include 16mat,14pat,6pat,2mat,20pat and XXpat but interpretation has been complicated by the presence of trisomy. 13mat and 22mat are unlikely to show imprinting effects

Evidence for genomic imprinting (http://www.ich.ucl.ac.uk/cmgs/genimp.htm)

more greek (http://www.ucalgary.ca/UofC/eduweb/virtualembryo/imprint.html)

Originally posted by (Q)
Spurious

[
I also concluded that the evidence for the other theories is equally flimsy...therefore you might doubt them too.

Darwin's theories imo, are not flimsy. They are good theories which abound in good evidence. What is it you doubt about them ?

i was not talking about evolution..but about the savanah theory etc....

Originally posted by (Q)
Spurious

To reason that the semi-aquatic population, which just allegedly spent 1.5 million years specializing in semi-aquatic living could out-compete the same ancestral population that spent the same amount of time further specializing in terrestrial living defies any Darwinian explanation.

I doubt that the aquatic theory can ever be proven or disproven. The evidence is intriguing but hardly convincing.

That said, and for the sake of science, I don't think the quoted paragraph holds water. (Yuk) As I said earlier, life in a three dimensional environment seems to be a stimulus for increasing intelligence. The hominids that crawled out of the lake and resettled on land undoubtedly had some physical disadvantages, but it's possible that their IQs had risen high enough to more than compensate and allow them to quickly surpass their cousins who never got their feet wet.

And just how big a disadvantage is a lifestyle that's only SEMI aquatic? You've got to be versatile and have two sets of well toned muscles. That could be an advantage! Polar bears are not just semi-aquatic but semi-marine, a pretty challenging combination of milieux. Yet in the few centuries since civilization began closing in on their habitat, they have proven just as clever and adaptable as the other ursines. At night they figure out how to open the latest model padlocked dumpster, and during the day they pose for cute tourist photos so the humans don't put much energy into running them off.

saw an interesting program on tv the other day. And although a lot of nonsense was mentioned they did manage to say one sentence that was interesting:

maybe it was not quite such a leap to go bipedalism for the human ancestor as we might think it was.

Bonobos for instance spend already a lot of time in the bipedal position in their forest habitat, therefore the arboreal lifestyle might have been not detrimental, but even instrumental in the evolution of bipedalism. Just a slight increase in selective pressure therefore might have done the trick.

I haven't the time to read through all the threads on this subject, but here's my input:

Why is it that humans have webbed feet and hands in their genetic blueprint? Below is an OMIM descriptions of such an anomaly, and there are plenty of others:


*185900 SYNDACTYLY, TYPE I
CLINICAL SYNOPSIS
Limbs :
Syndactyly
Complete or partial webbing between 3rd and 4th fingers
Fusion of 3rd and 4th finger distal phalanges
Complete or partial webbing between the 2nd and 3rd toes
No amniotic bands

Inheritance :
Autosomal dominant

Either our DNA is prepared for what might be possible in the future, or what has already occurred.

And...we certainly are dependent on the essential fatty acids present in the sea for the proper function of our brains. At the very least we should consider that our ancestors were dependent on seafood at some point in our evolution for survival. And if this is the case, perhaps we were able to escape predators, at least temporarily, by escaping into the water. We developed the ability to hold our breath for long periods of time because it facilitated capturing the fish, which is a whole lot less riskier than killing many land animals. Eventually we could swim to offshore islands? Maybe our evolution was accelerated by isolation on islands which other primates were unable to access. An isolated island lacking in vegetation may have driven humans to swimming as their main mode of acquiring food. Hair can slow a swimmer down in the water and it makes sense that humans would evolve with less hair in such an environment. the fittest swimmers lacked hair and passed this gene to their offspring. Jump forward countless generations and maybe the water level changed enough so that the new species of Homo Sapien were then forced to live on the mainland because some predator was able to habitate the island due to shallow water. And maybe we cannot find any links because the islands are now under water.

When I first started reading this thread I couldn't help but cringe. Not at the theory, which I happen to support, but the lack of understanding where evolution is concerned. I think it's so difficult to comprehend because people have trouble considering timespans of millions of years.

No, we didn't come out of the sea. We aren't evolved from mermen. Virtually all land animals are semi-aquatic to some degree. Water is a part of our environment and we must sometimes cross it during migrations or escaping from predators. Most mammals need to frequent water sources to survive. It is more imortant to our bodies than food. Interestingly though, the apes are exceptions to that rule. Most, including chimpanzee's, get sufficient water from their fruit diet. They cannot swim or hold their breaths underwater. Neither do they sweat very much. Survival dictates that excessive sweat glands are a no no for animals in a dry environment like Africa. Unless ofcourse they spend a great deal of time near and in water.

Here is the theory as I read it in The Aquatic Ape. Two main versions exist. I prefer the island theory to the River Apes so will give you the short version of that.

Species tend to mutate into new species when isolated. Millions of years ago environmental change forced new adaptations upon a species of primate ancestral to both Chimps and Humans. A rise in sea level flooded the Afar Triangle of North Eastern Africa wiping out most of the native flora and fauna dwelling there. Survival for apes in the region was a result of both posessing natural genetic advantages over siblings and blind luck. For survivors food was scarce and survival from then on became a daily affair of overcoming new obstacles and finding food.

The environment was similar to the Amazon now. Today, there are only two primates in the World that can swim and they both live there. Our ancestors had to find new sources of food and quickly found shellfish to be a nutritious substitute among the small islands. Frequently, when traditional food sources ran out on a small island, they would be faced with either making a hazardous journey across water to new islands or starving. Each migration had its fatalities as water was a strange and deadly environment for apes. Skip a million years and the picture changes but it isn't as smooth as that.

Several times over the period of mans evolution the isolated region opened up. Sea levels would drop for a time allowing the passage of apes out of the area. It's quite possible some found their way out in trickles during the flood aswell. This explains the large number of different hominids known to suddenly appear in the fossil record. Every time landbridges appeared new apes would leave the Afar Triangle. Chimpanzee's were among the earliest. Most nearly all are now extinct.

The earliest tools are thought to be spears and rocks. Rocks would have been an obvious tool for attacking shellfish. Even otters have learned this trick. Pointed sticks are just bigger versions of the twigs used by chimps today to get at termites. A longer reach for stabbing fish. Adapting to a semi-aquatic environment made us smarter and we quickly adapted our tools to land when the floods eventually receded for good.

"To reason that the semi-aquatic population, which just allegedly spent 1.5 million years specializing in semi-aquatic living could out-compete the same ancestral population that spent the same amount of time further specializing in terrestrial living defies any Darwinian explanation."

The land dwelling apes were already fully adapted for their particular niche. That of arboreal fruit eating climbers. Our diet of protein rich fish and later animals of the savannah allowed us far greater brain capacity. Our many new adaptations proved useful in carving out an entirely different niche. That of top predator. Dolphins compete very well against sharks by the way. For the same reason. Despite Sharks having hundreds of millions of years headstart they are slower than Dolphins, less intelligent, cold blooded and generally lone hunters. Dolphins were like dogs about 65 million years ago. Now they are the most proficient hunters in the ocean.

Until I read AAT I was always at a loss to understand human divergence. AAT isn't at odds with the Savannah Hypothesis. It supplements it beautifully. Everything is explained in a logical manner.

When I was 6 I had a branchial cyst removed. It was a one in a million thing and so rare that it was bottled and sent to a large hospital. I was told it was a 'fish gill'.
Background: Branchial cleft cysts are congenital epithelial cysts, which arise on the lateral neck from a failure of obliteration of the second branchial cleft in embryonic development.

"Phylogenetically, the branchial apparatus is related to gill slits. In fish and amphibians, these structures are responsible for the development of the gills, hence the name branchial (branchia is Greek for gills)."

Cthulhu

Everything is explained in a logical manner.

Is that why paleoanthropologists refute the AAT? Can you add anything other than hand waving?

Cthulhu

Our diet of protein rich fish and later animals of the savannah allowed us far greater brain capacity.

That would make crocodiles the most intelligent animal on Earth. Surely you must have something better than this.

fish in savannah regions? these type of regions is typically dry.
crocs? sure. but is it a typical habitat?

Between the wet equatorial belt and the subtropical desert regions are areas known as Savannah. They have a single short rainy season when the Sun is nearly overhead, whilst the rest of the year is dry. Vegetation consists mostly of scrub and grassland, which blossoms during the rainy period, and dies off during the prolonged dry season. Such climates and their associated land types are common in the Sahel in Northern Africa (south of the Sahara), large parts of India and parts of northern Australia.

i imagine it was pretty much the same during the pliocene

Dr Michael Crawford of the Institute of Brain Chemistry and Human Nutrition, London, Dr L Broadhurst of the USA., and other collaborators presented an unexpected and fascinating study. In his book The Driving Force: Food, Evolution and the Future (1989), Crawford explores many issues around "the land-water interface". To develop the large brain characteristic of the hominids, a chemical known as DHA was necessary. The lack of DHA in savannah food may explain the "degenerative evolution" of the brains of savannah species and the reason why Homo sapiens could not have evolved on the savannahs. The marine food chain, on the other hand, has an abundant supply of DHA. Early hominids had to make use of the marine food chain to enable the evolution of brain and brain size to keep pace with body size. Their claim that the human brain depended on the marine food chain suggests independent evidence in support of the importance of water in human evolution.

http://allserv.rug.ac.be/~mvaneech/outthere.htm


dispute the points that were put forward against a savannah scenario if you wish to maintain the hypothesis

edit: link inserted to counteract the heinous charge of eloquence

Not all palaeoanthropologists refute the AAT. It has recently seen a resurgence in interest. Evolution was refuted by most scientists in Darwins day. It takes overwhelming evidence to overturn theories many professionals have staked their professional careers on. At present there is little fossil evidence to support AAT. Which in fact would be expected since no digs are being undertaken at promising sites in the Afar Triangle.

I said that a high protein diet is necessary to support a large brain. I did not say eating a high protein diet automatically leads to development of larger brains. Spookz has eloquently explained it much further. We faced a challenging new environment which was intellectually demanding on us. At first we probably scavenged food left by the falling tide of this new inland sea. Later we became more daring and ventured out in search of it. The pearl divers of Japan demonstrate our remarkable talent for this. Our first adaptation would have been proficient wading ability. Keeping our heads above water and occasionally dogpaddeling back when it got too deep. This bipedal posture we posess didn't happen without an incentive. The same two primates who swim in the Amazon today have also been observed to wade in a similar fashion to human walking.

There is nothing unusual about this semi-aquatic behaviour. It is a common occurence in the mammalian kingdom for animals to return to water. Otters are a great example. Genetically they are almost identical to weasels. Divergence would have been very recent for the two. This new "water weasel" still shares much of its land cousins breeding customs. A male weasel for example grabs the female by the back of the neck during mating. Hard enough to draw blood. Otters mate in water where it is safer to mate face to face. As a consequence zookeepers know when breeding time has arrived because the female otters all have bloody noses.

Incidentally, we are the only ape to mate face to face. Certain evolutionary plumbing changes had to be made to make this form of copulation possible.

It's not just mammals either. In fact the only other creature in the animal kingdom to share our straight body gait with head balanced centrally atop the spine is a bird. The penguin. Another semi-aquatic.

Cthulhu

Not all palaeoanthropologists refute the AAT

Aside from the crackpots, yes. No credible palaeoanthropologist support it.

At present there is little fossil evidence to support AAT.

None exists.

The pearl divers of Japan demonstrate our remarkable talent for this

My neighbors dog demonstrated that too – so what?

Our first adaptation would have been proficient wading ability. Keeping our heads above water and occasionally dogpaddeling back when it got too deep. This bipedal posture we posess didn't happen without an incentive. The same two primates who swim in the Amazon today have also been observed to wade in a similar fashion to human walking.

Wading is proficient, but only to predators. Swimming is more efficient and precludes the need for bipedalism.

Incidentally, we are the only ape to mate face to face. Certain evolutionary plumbing changes had to be made to make this form of copulation possible.

False. We are not the only animals to practice ventro-ventral copulation – look it up.

The penguin. Another semi-aquatic.

That’s a funny one. The penguin is a bird and was bipedal before it was aquatic. By the way, what living semi-aquatic animal is bipedal?

Your argument is very weak and it appears you’re simply parroting Elaine Morgan and her followers.

Originally posted by (Q)
Cthulhu
At present there is little fossil evidence to support AAT.

None exists.

Chimpanzees' and humans' most recent common ancestor is thought to have lived in Africa around 6 million years ago. This estimate is based on differences between the DNA and other biomolecules of modern apes and humans. Fossil evidence is scant, and controversial.

Until February of this year, the earliest known hominid was Ardipithecus ramidus, which lived in Ethiopia around 4.4 million years ago1, some time after the divergence.

Then researchers working in Kenya claimed to have found a 6-million-year-old hominid; they called it Orrorin tugenensis2,3. Provocatively, they suggested that Ardipithecus ramidus was not a member of the human lineage at all, but was more closely related to chimpanzees.

The new finds, announced today by Yohannes Haile-Selassie of the University of California, Berkeley4, support the hominid status of A. ramidus and cast doubt on that of Orrorin. The fossils, from the Middle Awash area of what is now Ethiopia, represent an early form of A. ramidus, the team believes.

The resolution of this debate, if any comes, may have surprising consequences. At least one of these very ancient creatures could, in fact, be more closely related to chimps than humans. This would be an exciting result: fossils of hominids are notoriously rare, but fossils of chimpanzees are non-existent.

The same seems to be true for the older Ardipithecus announced today. Everything points to a woodland habitat for hominids living 5-6 million years ago, say Giday WoldeGabriel of the Los Alamos National Laboratory, New Mexico, and colleagues7. Orrorin seems to have shared this taste.

http://www.nature.com/nsu/010712/010712-14.html

why does aat and savannah have to be mutually exclusive? does affirming one theory automatically discount the other? as indicated in the nature article, including a woodland habitat would bring us closer to a mosaic type scanario. i believe there was a reference to the mosaic in an earlier post. all indications are that the savannah was an inhospitable region for hominids. this does not have to mean it was not populated.

the next article is especially for you brother q!

;)

My critics said AAT was unnecessary. They claimed that the scenario for the ape/hominid split was well understood: one population of the ancestral apes moved from forest out into the "hot, dry savanna". There, they became two-legged so as to "run faster" and carry weapons, while the torrid heat caused them to sweat profusely and shed their body hair. AAT referred to all this as "the savanna theory". In different versions, it reigned supreme for over fifty years.

In what for me has been a remarkable and exciting development, the experts have in recent months suddenly started to abandon this whole idea. Detailed studies of the African paleoenvironment show that savanna conditions evolved in Africa much later than had previously been imagined. The habitat of Lucy (Australopithecus afarensis) is now agreed to have been "lush and well watered" (her bones lay among crocodile and turtle eggs and crab claws).

Australopithecus ramidus, a million years earlier still, lived in woodland. Richard Leakey wrote in 1992: "The great plains and the immense herds on them are... much more recent than the origin of the human family". And now Professor Phillip Tobias, lecturing in London on his recent fossil discovery "Little Foot", has announced that "the savanna hypothesis" (of which he had been one of the most illustrious supporters) "is washed out".

Is this the beginnings of a paradigm shift completely revolutionising our understanding of human origins? I think it could be. The strength of savanna theory lay in its contention that the hominids' habitat was radically different from that of the apes. This claim is severely undermined if the protohominids were largely tree-dwelling, as is now agreed, only crossing open spaces in occasional transit from one patch of forest to the next.

Meanwhile, AAT is waiting in the wings. The arguments against it look increasingly precarious. Nearly all the Rift Valley fossils were recovered from lake or river sediments. Unfortunately, this can never prove that the entire species lived by the water, since only bones deposited in watery sediments get preserved. On the other hand, neither can it disprove the idea. If the first hominids were indeed largely tree-dwelling, why did they and no other apes become bipedal on the ground? A flooded forest offers a possible answer: there is geological evidence of extensive flooding in the areas where the oldest hominids are found.

The strongest argument for AAT is the number and variety of Homo's unique features, for some of which the aquatic explanation is the only one on offer. These anomalies are not a common subject of research. Many specialists still find them simply distracting, and sometimes respond "We may never know the reason" or even "There may not be a reason".

But the questions will not go away. Professor Tobias enjoys being back at square one. "A change of paradigm", he says, "shakes us up; it rejuvenates us; and this above all, it prevents mental fossilisation - and that is good for all of us". (morgan)

http://www.llb.labournet.org.uk/1996/april/sci.html

i would like to be able to dispute her claim of a flooded forest and wading as an impetus towards bipedalism.

As far as I know there have been no expeditions to the Afar Triangle in an effort to find evidence. I wonder if enough support and funding could be gathered for such a venture. It might prove fruitless but if successful would revolutionise anthropology. Theories regarding human origins would have to be rewritten. I'm only an amateur Palaeontologist but it might depend on recruiting enthusiastic amateurs. I'd be more than willing to make such a trip myself. How does a person go about arranging this kind of adventure? You only have to do a search to discover that squillions of people would volunteer for it. Money is the only problem. Approaching potential sponsors might work. Otherwise I could establish a fund and beg for donations I suppose. One good thing about the internet is Paypal.

Destination for the dig? Danakil Island most likely.

Cthulhu

I see you've returned as SciAuthor. Is there some reason for the deception? Are you going to advocate your own AAT assertions? I find it hard to believe my last post was the definite nail in the coffin, so to speak.

What gives?

Just my opinion on the AA theory... I think it has lots of relevance but needs more proof before it can topple the existing theory. It would explain body fat layout, head hair spiral, webbed feet, and our strange lack of normal primate body hair!

Originally posted by WellCookedFetus
our strange lack of normal primate body hair!

i take it you aint caucasian huh?

;)

Nope how you guess... but latinos have that kind of hair too (just worse!) very VERY few people have hairs as thick as a chimp though.

No deception. I just didn't like the look of Cthulhu1. I'll try to answer your last post then. Your statements were so definitive I assumed you wanted no reply.

"Aside from the crackpots, yes. No credible palaeoanthropologist support it."

Untrue. Some leading scientists support it. Majority is no indication of correctness.

I said...
At present there is little fossil evidence to support AAT.

"None exists."

Untrue. Shells have been discovered from the time period relevant with scratches identical to those which would have been made by early hominids. Proof that they supplemented their diet with shellfish. Countless physiological traits match those to be found in semi-aquatic animals. Why did our ancestors jaws and teeth diminish? Clearly shown in the fossil record. A diet change from fruit to tough meat would not lead to weakened eating apparatus. Even Lucy was found in an ancient lakebed. How is it that fossil man is found in almost every part of the World. Apes have a natural fear of deep water. Some places were only crossable by sea.

The pearl divers of Japan demonstrate our remarkable talent for this.

My neighbors dog demonstrated that too – so what?

Try teaching a Gorilla.

Our first adaptation would have been proficient wading ability. Keeping our heads above water and occasionally dogpaddeling back when it got too deep. This bipedal posture we posess didn't happen without an incentive. The same two primates who swim in the Amazon today have also been observed to wade in a similar fashion to human walking.

Wading is proficient, but only to predators. Swimming is more efficient and precludes the need for bipedalism.

No doubt. But you must walk before you can run. People who cant swim wade. Its easy. We have the natural balance of a sea lion. Standing tall keeps your head out. As I explained, this is eactly what two species of monkey do in the Amazon. Swimming and diving came next.

Incidentally, we are the only ape to mate face to face. Certain evolutionary plumbing changes had to be made to make this form of copulation possible.

False. We are not the only animals to practice ventro-ventral copulation – look it up.

I said Ape.

The penguin. Another semi-aquatic.

That’s a funny one. The penguin is a bird and was bipedal before it was aquatic. By the way, what living semi-aquatic animal is bipedal?

I know its a bird and said so. Bipedalism was not what I said. Its body is straight like ours. Head situated directly above the spine. An unusual trait only shared by us. Another aquatic. Perhaps just a coincidence. Perhaps a case of parallel evolution.

Your argument is very weak and it appears you’re simply parroting Elaine Morgan and her followers.

AAT is far more logical than the Savannah hypothesis standing alone. Look at Babboons and you will see the results of savannah on Apes. Our physiological makeup shares little with Babboons and no major evolutionary changes happen without being forced. How could predators have instilled such change? We are slow running, sweat profusely, are fat, have no sharp strong teeth or claws. How did we survive before tools were invented? The only other possible force of change is environmental. A drastic change in the land. Only flooding fits and we know north east Africa was flooded at the right time.

birds went bipedal because of an adaptation to flight. Therefore they cannot really be used as an example for aquatic bipedalism. The aquatic adaptations in penguins are secondary adaptations. That said, there doesn't have to be any analogous example of a bipedal semi-aquatic animal to proof that humans bipedalism was facilitated by a semi-aquatic period. We could have been the single example ever and it would still be valid.

I think that most people make the mistake that there is plenty evidence for any of these theories. This leaves the suggestion that the evidence for the AAT is so weak that the savanna theory must be right since there is so much evidence for that. But of course there isn't really.

I've said it once already but I'll repeat it again. Q misquoted me. I never said anything about bipedalism.

birds went bipedal because of an adaptation to flight.

Not so but an easy assumption to make. Birds are descended from small bipedal donosaurs. They evolved bipedalism to increase running speed. Clearly this is not the reason we developed it. We are the slowest of the great Apes.


We are more than just bipedal. Birds have a forward stooping gait balanced by a tail. Except for the penguin ofcourse. It's back is straight and its head connected centrally atop the spinal collumn rather than slightly forward. Just like us. Would you argue that Penguins aren't semi-aquatic? What would happen to them if they were suddenly forced to live in savannah? They would likely seek out rivers and lakes if they survived(dubious). We went from a semi-aquatic existance to savannah but had hands with which to use tools. We had learned to use rocks on shells and spears on fish over a million years or so and took these skills with us. We took shelter where possible in rivers where big cats did not like to follow but this shelter was not always available. The weapons kept us alive on the open Savannah. We were forced to become more proficient with them or else face extinction from big cats. In time we went from defending to attacking. During dry spells there would have been insufficient food in rivers. So we went after other game.

Originally posted by SciAuthor Birds are descended from small bipedal dinosaurs. They evolved bipedalism to increase running speed.[/B]Why does bipedalism improve running speed? I'd think the higher center of gravity on fewer supports would divert energy from locomotion into balancing. And a vertical stance would create more wind resistance. Bears seem well adapted to both postures but they drop to all fours when they want to run.

Just curious, you seem to know this stuff.

as i seem to remember cheetahs are the fastest land animals (a bit of your own reasoning)..i forgot if they were bipedal..

and please could you give us the explanation why bipedalism came about on the savannah and what the evidence is?

I haven't read the thread so sorry if someones already thought of this but:
I'm starting to think we might be aquatic apes, here is how it could have happened, the original primate ancestor would have split up and gone its seperate ways, some of them may have ventured into shallow water and started eating mollouscs and crabs or whatever. I'm assuming it would have become a hassle bent over in the water all the time and an obvious beneficial stance for wading would be upright. On the flipside there is NO natural benefit in standing upright on land. I can't see why we would have evolved like that unless we were wading.
I'm sure its our skin that started this so I won't even mention it.
But all the other primates of today are uncomfortable swimming (except for the macaques who only get in hot springs because of how cold it is outside them) but we not only feel comfortable in water we love it.

Originally posted by Dr Lou Natic
I haven't read the thread so sorry if someone's already thought of this but...Six pages of postings, I think everything's already been said at least thrice. You should check it out, it's a fascinating subject, all the more so since it's unlikely ever to be resolved.

oops my bad

aaahhh good work fellas!!! :D

:(

Spot on Dr Lou. That is the most popular aquatic ape theory. In fact two species of monkey living in the Amazon have been observed to wade in that exact fashion. The proboscis monkey has even been sighted several kilometres out to sea. Although the river apes hypothesis is gaining ground. Only isolation causes divergence so I'm more inclined to go with Danakil Island as the cradle of humanity. When sea levels dropped and humans were forced to live in open savannah they no doubt sought out new water sources immediately. A river ape scenario might then have played itself out. In fact some people might argue it is still being played out. Most major cities are situated on rivers and coastlines. Fishing is probably the oldest recorded form of work.

http://www.myk.org.uk/d1x/asia/probscis/0341z.jpg

Longest nose in the Primate Kingdom. Humans only have the longest nose in the Ape kingdom. Proboscis monkeys are expert swimmers and the whole troop will jump into the water if startled. They have webbed toes. Monkeys are a lot smaller than the great apes and smaller animals who spend a great deal of time in water retain their fur. Small body mass means rapid loss of heat. Thats why creatures like Otters, Beavers and Coypu's maintain a coat while larger animals usually don't. Exceptions to the rule are animals living in extremely cold climates where even the trapped heat within specialised fur is worth keeping. Fur seals for example.

A long nose might be designed to keep water out. All apes except humans have two holes as a nose. Further adaptation might lead to a trunk as seen on the Elephant. Another animal thought to have once been semi-aquatic. Just like the Hippo still is today. Difficult to tell since animals of that size don't need a fur coat in warm climates.

Originally posted by SciAuthor
http://www.myk.org.uk/d1x/asia/probscis/0341z.jpg
Oh yeah, I forgot about those dudes, they swim alot also. I remember seeing a documentary that showed them jumping out of high trees and splashing into the water in slow motion, they looked funny as hell with their big noses flopping around. They made hilarious facial expressions to.
Actually they'd have to be the most humanesque of the monkeys, they look and act like alchoholics with their potbellies and red faces.

It would be funny if people did evolve trunks:p That would piss us off immensely considering our vain nature.
I hope I'm the first to have a trunked baby:p I better start nearly drowning on a regular basis.

A big nose probably does help to some extent in water. Two holes in your face doesn't keep water out much. Remember that most wild animals die before reaching adulthood so any advantage whatsoever can influence your chances of survival. Over millions of years you can expect to see desirable traits emphasised. Ofcourse, evolution is influenced by many things and a big nose among proboscis monkeys has probably become a sexually desirable trait. Like peacock feathers. I wouldn't be surprised if the direction of fur growth has become more streamlined. That is growing in the same direction as the water would go past the body when swimming. This is an early adaptation to water before fur is lost completely. Human babies in the womb have a fine down all over their body which is lost before birth. A leftover ancestral trait. It grows in just such a fashion. Other apes do not share peculiar swimming adaptation. The fur on the proboscis monkey seems quite short I notice.

Don't know if it was cited, since I was looking for something else in the search, and I didn't read all the discussion. Anyway, here's a good site on the subject: http://www.aquaticape.org/

Cthulhu

Our diet of protein rich fish and later animals of the savannah allowed us far greater brain capacity.

That would make crocodiles the most intelligent animal on Earth. Surely you must have something better than this.

Isn't that an argument you can hold up to EVERY supposed 'benefit' that enabled some kind of change? Supposedly, (cooked) meat enabled homo to develop larger brains... at least, that's what I learnd in my courses. The question is: will it make your dog smarter? Now I read in 'An introduction to brain and behavior' (Kolb, B. en Whishaw, I . Q. (2000) An introduction to brain and behavior, New York) that it is possibly a diet mainly consisting out of fruit that helped our brains to become larger. Supposedly, fruit poses lots of challenges which needs to be faced (different seasons, knowing the right trees, etc.):


What is so special about eating fruit that favors a larger brain?

Fruit does not contain a brain-growth factor, although it is a source of sugar on which the brain depends for energy. The answer is that foraging for fruit is a difficult, complex activity. Unlike plentiful vegetation within easy reach on the ground, fruit grows on trees, and only on certain trees, in certain seasons. There are many kinds of fruits, some better for eating than others, and many different animals and insects comete for a fruit crop. After a fruit crop has been eaten, it takes time for a new crop to grew. Each of these factors poses a challenge for an animal that mostly eats fruits. Good sensory skills are required, such as color vision, to recognize ripe fruit in a tree, and good motor skills are required to reach and manipulate it. Good spatial skills are needed to navigate the trees that contain fruit. Good memory skills are required to remember where fruit trees are, when the fruit will be ripe and in which trees the fruit has already been eaten. Fruit eaters have to be prepared to deal with competitors including members of their own species. To keep track of ripening fruit, it also benefits to have friends who can help search. As a result, succesful fruit-eating animals tend to have complex social relations and a means of communicating with others of their species. In addition, it is very helpful for a fruit eater to have a parent who can teach fruit-finding skills, so it is useful to be both a good learner and a good teacher. Each of these abilities require the evolution of new brain areas or more brain cells in existing brain regions. Added up, more brain cells produce a larger brain.

So, hunting is less complex than this? ... Requires less social skills? Demands no good spatial skills? ... I'm not convinced.

I think you get the site record for reviving a long-dead thread. :)

Q is wrong and Cthulhu is only partly right. Protein only works in conjunction with other metabolic advantages, like being warm-blooded. Warm-blooded animals--mammals and birds--absolutely rule the water when they get serious about adapting to aquatic life. Whales, penguins, polar bears, seals, ducks, otters, gulls...

Reptiles can't evolve big brains because their slow cold-blooded metabolism can't provide enough nutrients, no matter how much protein they eat.

Hunting promotes a certain kind of intelligence, but speed and strength are more dominant attributes. Scavengers and omnivores generally are at the top of the IQ pyramid within their genetic group. Bears, raccoons, rats, parrots, crows.