Boris:
But is it truly proper to separate mammals from other forms of life? You seem, for example, willing to admit that macroevolution occurs in birds. But what is the real difference between birds and mammals? Is it really intelligence, or "neural net complexity"?? Compare a raven to a gerbil -- which one do you think has a more complex cognitive apparatus?
It is important to realize that mammals are not in any way special as a lifeform. We are still macro-organisms composed of trillions of cells. We are still realizations of our DNA. We still reproduce, and we still undergo genetic variation. As a biological system, we are fundamentally, at our deepest level, no different from a bacterium. So really, what is it that makes you segregate the mammals in particular into such an exclusive group that does not evolve even though all other life on Earth does?
Boris: Thanks for the long answer. I really enjoy talking about this with you. Of course, you realize that in the end neither of us may change the other’s mind about this subject and that’s ok with me however, I do hope that you can help me refine my thought or show me where I may have made a misstep.
Here’s my response: I am not sure what you mean by “proper”. I suppose you mean either “appropriate” or “correct”. Yes, any means whatsoever are correct or appropriate when one is trying to establish the truth about something. If a theory is absolutely correct it can stand up to the closest scientific scrutiny possible. Mammals have been segregated from the rest of the animal kingdom since classifying was first started. They are any of various warm-blooded vertebrate animals of the class Mammalia, including human beings, characterized by a covering of hair on the skin and, in the female, milk-producing mammary glands for nourishing the young. To lump them with every other life form may confuse the issue if we are to understand the mechanism of life. At least to do so leads one toward a reductionistic error. You say that we are at our deepest level on different from bacteria. That may be true as far as life in concerned but at the deepest level we are no different from anything else, i.e. subatomic. I do not think that will help us understand the mechanism of life. Fundamentally in our effects, we are WAY different from a bacterium. This is incontrovertible.
My point is that we can find all sorts of life forms speciating except mammals. Now, as a scientist, that makes me curious. Doesn’t it make you curious? I mean, if evolution is the ultimate mechanism for ensuring the survival of life, which as you know IS evolution’s war cry, then when I find an anomaly in the mechanism I look to THAT anomaly to help me refine it. That is how science works. That was why Einstein was able to refine Newton’s theory of gravity. He found the anomalies. To run from them or try to interpret the findings to back up a favorite portion of a theory (like the part that says ALL life evolved) is BAD science.
When I began to notice that mammals didn’t speciate I didn’t know what to do with that. I looked at the differences between them and other animals. One that was striking and might be the most helpful was the brain. The brain is the ultimate organ of our known universe. To find striking differences there might be a clue to survival, which is turn, is what evolution is about, in other words, no survival, no evolution, it is a necessary condition for evolution. If you study mammalian brains you will find that the gerbil has it over the raven many times. Mammals are the only creatures that have convolutions in the brain, not only that but the more convolutions the higher the level of cognitive ability. One even has a deep crease that runs from the anterior lobe all the way across the top of the brain and all the way down the back and THAT creature is incredibly different from all others, you know the one I mean, Homo sapiens (Wise man). You stated that mammals are not “special”. If you mean at the basest level, you are correct but if you mean at the most obvious level you are mistaken. It is obvious that mammals are different elsewise they wouldn’t have a classification all to themselves. It is also obvious that man himself is different. To reduce man or anything else to its subatomic particles doesn’t help us at all when we are trying to understand the effects of things. When you study subatomic particles individually, you can learn about their individual effects. To learn about a particular thing you have to study it in toto to learn about it’s effects. There is a vast difference between parts and wholes. That is a fundamental law about the nature of the universe. If you take the ingredients of a 7 course meal and mix them in a bowl and cook them without the proper order you can call it a meal if you like but many would disagree. Man himself is radically different from every other life form for man has an intellect. That should properly be the subject of another thread so I won’t elaborate much on it here other than to say that the immateriality of the intellect cannot be properly understood without looking at it’s effects and actions in toto.
Would you agree that wholes and parts are different?
I suppose it would help if I elaborate a little on what I believe about macroevolution. I believe the certain life forms can and do speciate but they do so only once. That is what I can readily observe in nature. I believe that they can do that in order to survive. Some cannot speciate at all, I can also observe that if I look for the evidence and use the process of induction. Ask any mammalogist, mammals have never been observed to speciate. As far as the poodle versus the wolf, the same can be said of the poodle and the Irish Wolfhound and they are the same species. No biologist would say otherwise. When a species cannot have a fertile offspring from the union of a sperm and egg they are considered separate species, not until they have passed that test can they be called distinct.
So wait a minute. Do you accept the fact that clinal variation exists in mammals, or don't you? You seem to be contradicting yourself...
Sorry for the confusion. I mean that clinal variation exists in mammals but we do not see it leading to speciation. After all that is the primary place to look for speciation. We see clinal variation leading to speciation in all other forms of life but mammals. That anomaly needs to be investigated closely if we are to ever understand the mechanism of life, including evolution. The geographic pressure on Cryptotis parva is great to evolve into separate species. North/south clines are where you find it in other forms of life. It is incontrovertible (by the way, I like that word) that the environment through the latitudes between Ontario, Canada and the Panama Canal changes radically and it is that sort of wide variation in geography that leads to different species. The different variations of Cryptotis parva has vastly different morphological features, yet it can still interbreed and produce fertile offspring. If it were another life form other than a mammal it would not be able to. Long before now it would have speciated. That anomaly should make a person curious if they are curious and evolution hasn’t closed their mind. But it is not a singular case when it comes to mammals, you can find many different examples of it and you don’t have to look hard. As I mentioned, Canis lupus var. familiarus provides us with another startling example and one that is commonly known to lay people.
You lost me here. Why would I form such a conclusion, necessarily? And if I did, would I really have been wrong? (remember the example of a wolf and a poodle?) Of course, there are always questions of how much of a fossilized difference in morphology is attributable to within-species variation vs. between-species; but this is only true for fossilized lifeforms that could at least in principle belong to the same species. Obviously, fossils exist that could not have possibly belonged to the same species.
Sorry, I didn’t mean you personally, I meant anyone studying the fossils. Yes, I remember the wolf and the poodle and they are the same species. NO biologist would say differently. It is a good example of what I am talking about. You were right that it would be an unlikely mating but unless it is COMPLETELY IMPOSSIBLE they are the same species.
You have a good point about the “fossilized difference in morphology is attributable to within-species variation vs. between-species”. That fact points to the conclusion that unless we are studying live animals we may not know and in some cases will never know if a two different fossils were from two animals that could interbreed and produce live offspring.
Point well taken, but this is only a minor problem with fossil classification of more interest to paleontologists than to evolutionists. What evolutionists see in the fossil record, is fins slowly being transformed into appendages, appendages into arms, spiny radiations into fingers, first rather crude, and then articulated. What evolutionists see in the record, are scales transformed into feathers, and feathers into fur. Evolutionists see separate and articulated toes slowly loosing their articulation and converting into a hoof. In other words, evolution is concerned with morphology, not with exact fossil classification.
What we have in front of us, is overwhelming and incontrovertible evidence of common ancestry for all animal life. Here, fossils are not even a dominant part of the picture; what is even more significant are all the lifeforms currently alive today. The morphological evolution is evident in everything, from the ears, the eyes, the tongue and other senses, to the teeth, the spinal column, the tail, the appendages, the skull, and other skeletal features, to the brain, the lungs, the intestines, the heart, and other internal organs, to the skin, the fur, the nails, and other epithelial layers.
Of course, such phenotype morphology derives directly from genotype morphology. Hence, it is little wonder that oftentimes, the DNA of organisms that look similar is also similar (with the exceptions being representative of what is called convergent evolution.) And it is when we look at DNA and how it is replicated during mitosis, that we find the most important of all the mechanisms that drive evolution: transcription errors (though it is certainly not the only genetic mechanism at work.) This is where a mathematical case for evolution begins, and indeed the case is of the open-and-shut variety.
It should be of interest to evolutionists as well because the “theory” of evolution had it’s beginning there. Like the sights on a gun, errors in the beginning can produce extreme errors in the end. Evolution had some things that needed correcting when it was first postulated but instead the bulk of the scientific community proliferated those errors until it was WAY off track.
To be precise, what evolutionists “see” is a wide variety of life forms. They postulate that they evolved. It is an assumption that can only be corrected by looking at what happens evolutionarily speaking, today, looking at what life does in fact do, and what it does not.
Phenotype morphology does derive from genotype morphology. And though the math may be compelling we need to observe in nature what indeed does happen not what might be able to happen. When you speak of and open and shut case, two things. Does macroevolution occur? Yes, it does and we have no definitive proof that it only happens more than once. As far as mammals are concerned, we have no proof that even happens once. And secondly, we need to be sure our minds have not opened and shut on this important issue. To do so is to make the mistake that many in the scientific community have made time immemorial, namely, that the theory of evolution needs further refinement. After all, Newton thought he was right too.
What we have in front of us, is overwhelming and incontrovertible evidence of common ancestry for all animal life.
What we do have in front of us are facts that need careful interpretation. The evidence is neither overwhelming (if it were it would have convinced all of the scientific community) nor incontrovertible ( if it were this discussion should not be taking place).
Well, you are making a couple of assumptions here. First of all, you assume that the organism in question indeed is under pressure to evolve. But in fact, if it's already well-adapted, if it reached a local maximum on a genetic fitness landscape, then it will indeed tend to remain at this maximum and preserve its genotype across millions of years. This is not the only such known example, by the way, and there are other such examples for non-mammalian species. For example, horseshoe crabs and coelocanths come to mind. Secondly, you assume that even though a species has maintained a certain appearance through time, it did not branch off into other species. However, it is indeed very common for a species to simply spawn off subspecies that eventually, with time, develop into entirely separate species -- all the while the parent species continues to happily maintain its original form and function.
I made neither assumption. Firstly, it is far more than an assumption that the organism is under geographic pressure to evolve. If you look at the various environs that Cryptotis parva lives in you will see that far less drastic changes have produced speciation in other life forms, yet in Cryptotis parva it has not. When we examine the surrounding fauna that exists near it when find no living creatures that appear to have been linked with it nor do we find fossil evidence of the same. Now, how do you explain that?
I understand that certain creatures maintain their genes intact within the unit of their species. Did you seriously think I didn’t?
First of all, just what kind of "other evidence" is being asked for, here?
I am asking for us to observe a species evolve into a separate genus. This is not as hard as it might seem. There are ways that you can accelerate the evolution of certain life forms. Smaller life forms have been made to replicate 10,000 generations in a lab in a very short time, i.e. bacteria, etc. If we can do that we need to further accelerate their generations until they evolve into a separate genus. That wouldn’t be hard to do if evolution works as well as some in the scientific community says it does. The point is that they haven’t had success at such an experiment and my opinion is that they will not try it because it is doomed to fail. Species do not cross the genus line anymore than mammals cross the species line.
A way to disprove evolution, is to take its assumptions, and deductively form a prediction that does not agree with observations.
Evolution assumes that mammals evolve. Where is the observation to prove it? To find mammals evolving you have to see evidence of it in the creatures themselves, not their genetic structure. Just because a life forms has the ability to evolve means that it does. I am not so sure that you can find the ability by looking at mammal’s genetic code in any event.
Secondly, it seems the author is approaching the elephant from the wrong end. The fact that the "line of speciation" is a real phenomenon, is a consequence of evolution, not its driving mechanism.
I am not sure what you mean here unless it is reductionism.
A cline establishes initial variation across a species; as it persists, genetic variability accumulates at its opposing ends, giving rise to genetic drift. With enough time, the opposing ends of a cline drift so far apart, that they form distinct species. This is just one of many types of scenarios that give rise to macroevolution. And it is so eminently reasonable, it puzzles me anyone would argue against it.
Yes, and where is the evolution of Cryptotis parva? You have answered an earlier question of yours. I noticed here you mentioned nothing about geographic pressure. You are right there actually doesn’t need to be any. In the case of Cryptotis parva there is, but the species has been existing along a cline for millions of years without producing a new species. Why? And if it is so reasonable where is the evidence for it when it comes to mammals?
As an interestig examle of microevolution in mammals that was on its way toward producing entirely different species, consider Homo Sapiens itself. Clearly, geographical separation has resulted in genetic drift that gave rise to what we call "races". The process was interrupted at an early stage through the development of global human civilization, and it is being reversed at this very moment through accelerating inter-racial breeding. However, it is not such an incredible stretch of imagination to see that, were the modern human civilization to be forestalled for another million years, enough genetic difference might have accumulated across the "races" to render them unable to interbreed -- hence branching the Homo Sapiens out into multiple descendant species. In fact, this sort of thing seems to have happened in the past with our precursors. The fossil record indicates that early hominid species branched out many times all over the globe. However, invariably the different hominids ended up dominated and exterminated by a single contemporary hominid that proved to be somehow stronger. This is due to the fact that our species (as well as our close ancestors) adapt so well, and hence were able to migrate virtually anywhere in the world.
Actually, there is a VERY heated debate going on in the anthropological community right now about whether there are races or not. Clearly, if specialists in a field cannot agree on your first premise who are we to build an argument on such an unstable foundation.
The fossil record? Regarding hominids? Now there’s REAL proof for evolution. And just how many different hominids have they found? Please give a number. I know the answer to this one VERY well. I live near Cleveland Ohio. Our museums' team was the one who found Lucy.
This was not what I was trying to point out re. development. What I was alluding to, are the various features present in human fetuses -- such as tails, gills, a spinal tube, etc. In fact, in early stages of development a human embryo is morphologically indistinguishable from other animal embryos (even fish embryos!), which strongly suggests that we started at the same "base", and then simply proceeded to "upgrade" the product.
Strongly suggests is another term for an assumption. Would you care to discuss Haeckel’s forgery? Think of it, would you have every species have a different base another than DNA and every embryo look like a little copy of it’s adult form just to prove to yourself that evolution isn’t true? That would be absurd.
As I mentioned, evolution is not based on the type of induction you insist upon. We do not say that just because species X evolved, then all species evolved. This might have been how evolution theories got started, but we have progressed centuries beyond such simplistic reasoning. Now, we understand life at a level comparable to understanding metals at a subatomic level. With such an understanding, we no longer generalize genetic change; we indeed postulate it based on our knowledge of life's inner mechanisms.
Yes, unfortunately evolution is based on that error and it needs correcting. The second error is to say that parts have the same characteristics as the whole which is what you refer to when you say “Now, we understand life at a level comparable to understanding metals at a subatomic level. With such an understanding, we no longer generalize genetic change; we indeed postulate it based on our knowledge of life's inner mechanisms.”. This is an error of reductionism, also known as the fallacy of division in logic.
Have fun
Yours,
Adlerian
[This message has been edited by Adlerian (edited May 14, 2000).]