Why is natural selection not random?

Emil

They are many and varied. Mutation produces DNA with changes, most of which are fatal or neutral, but a few give traits that give a reproductive advantage. In addition, DNA does not throw things it has found to work away, it keeps DNA for traits that may not be expressed until there is great stress on the genome or even the presence of certain predators or parasites, transcription errors can switch the places of sections of DNA, which may or may not affect survivability or cause disease or malformation and your DNA is mixed with other DNA, each having it's own mix of traits, sexual reproduction became so dominate BECAUSE of the mixing of different genes gives MORE variation for Natural Selection to test. A bacteria has much less variation(but much faster reproduction)because it's DNA is largely(but not completely)seperate from that of other bacteria.

Grumpy

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What are you talking about?
I have no idea what this means.

 

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:bugeye:
I have no idea what you mean. How many different ways can it be defined? If you're getting different definitions, you're probably reading the wrong material. Books with titles like you cited above are obviously not interested in biology. You would obviously need to read biology to get the right answer.

When asking about science, it's best to pick an authoritative source.

Natural Selection: Differential survival and reproduction of organisms as a consequence of the characteristics of the environment.​

If your eyes get tired reading the thousands of journal articles that encompass natural selection, you can also turn to audiovisual lectures and talks, such as this presentation of selection in action.

Since it's a topic of science you can obviously find any number of universities or schools with teaching materials.

What's the issue? I don't get it.

And what's the issue about randomness?

:shrug:

Will the bird see the uncamouflaged mutant bug? Probably. Eventually. Most of the time.

What difference does randomness make for the bug? He's maladapted.

From that standpoint, the game of chance is over. Eventually his phenotype will die out.

What does "directed" mean? It has the ring of creationism in it.

Where's the controversy?

:shrug:

 

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My definition of natural selection somewhat resemble which other poster has told:-

"Natural Selection: Differential survival and reproduction of organisms as a consequence of the characteristics of the environment."

One Definition of natural is :based on inharent sense of right and wrong and when we use natural in natural selection, it should be selection based on inharent sense of right & wrong.

 

The environment sets potentials. There are certain cause and effect scenarios which will minimize the impact of the potential. Relative to natural selection, the potentials establish their own selective cause and effect relative to optimization.

Say you were near a campfire and the wind starts to swirl. There is a moving sweet spot where you will breath the least smoke and get the best air. If you walk randomly to the beat of your own drum, without regards to smoke direction being established by the wind, you will breath too much smoke. Natural selection is like a dance where the potentials are leading, not the DNA. The DNA will establish variety so there is the capacity to find the sweet spot.

If the weather turns bad due to global climate change, this sets a new range of potentials for life. If life can minimize the impact of these potentials, they will have selective advantage. The sweet spot will result in the least physical resources needed and the least wear and tear on the hardware.

 

Let's be honest yeh! Please see this thread alone, users have so far given multiple meanings for natural selection.

According to the following sources natural selection is:

Google Dictionary

Medical dictionary

Parker, S. P. (Ed.). (1997). McGraw-Hill Dictionary of Bioscience. New York: McGraw-Hill.

http://wordnetweb.princeton.edu/perl/webwn?s=natural selection

http://en.wikipedia.org/wiki/Natural_selection (old version)

http://en.wikipedia.org/wiki/Natural_selection (new version)

http://www.oceanlink.info/glossary.html

http://www.mhhe.com/biosci/pae/glossaryn.html

http://www.sciencelearn.org.nz/About-this-site/Glossary/(namefilter)/n

http://www.ncbi.nlm.nih.gov/books/NBK21126/

www.whatislife.com/glossary.htm

http://www.enchantedlearning.com/subjects/dinosaurs/glossary/indexn.shtml

mitpress.mit.edu/books/FLAOH/cbnhtml/glossary.html

web.missouri.edu/~flinnm/courses/mah/glossary.htm

www.streamnet.org/glossary.html

http://www.csrees.usda.gov/nea/biotech/res/biotechnology_res_glossary.html

American Heritage Dictionary

http://science.yourdictionary.com/natural-selection

http://dictionary.kids.net.au/word/natural_selection

http://www.vocabulary.com/dictionary/natural selection

http://www.collinsdictionary.com/dictionary/english/natural-selection

National Geographic Glossary

Michael A.Park, Introducing Anthropology: An Integrated Approach, 2nd Ed., glossary

Pretty much all DIFFERENT answers!

 

They pretty much all say the same thing, except for the definition supplied by vocabulary dot com which was just stupid and inaccurate.

 

darryl,

It's not that complex. Random "selection" would imply that individuals die randomly, that their reproductive success is random.

But we know that survival and reproduction rates are not random, but depend to a huge degree on the fitness or individual traits of the living thing. As long as your DNA code affects your fitness and ability to survive, it will influence whether you live or die to a larger or smaller degree. So, this means that non-fit DNA code will be weeded out of the gene pool as those less-fit individuals die sooner. Thus, evolution!

 

Fitness is a relative term.
Very relative.

Fitness could be whether or not you strike a good first impression with a breed-able female, regardless of faulty genes. If the genes are so faulty that associated health problems begin to affect individuals prior to breeding age, that species faces extinction. What happens after that is well... fair game.
Clearly, we're not exactly built to last...

Does the Banana Slug look especially fit to anyone? How about that Octopus? I don't care what any of you say- that's prime breeding material right thar!!

Fitness can be defined for Evolution as : Good enough to not go extinct, given that the environment doesn't change drastically.

Fitness as strength only comes into play when discussing competition for resources.
A desert shows many fit animals, but a small amount of diversity.

A rainforest shows extreme diversity- with animals that wouldn't last very long if they were placed elsewhere.

Transplanted animals can wreak havoc on an eco-system in competition.
Obviously, rats are more fit than the Dodo. Or is it that humans are more fit than the Dodo?
Odd considering that the Dodo was an ancient creature.

And then you have blind cave salamanders. How did being blind make them strong and fit?
Well, it didn't. But lacking eyes in total darkness is an advantage, as the soft and susceptible eyes can very easily be injured in the dark leading to lethal infection. Plus, anxious females can't see if you have eyes or not. They'll still do a mutant that has no eyes. The genes are introduced by that breeding and show a slight advantage over the salamanders with sensitive little eyeballs in the dark. Sure the process takes a very long time, but as long as they keep successfully breeding--- They are FIT.
http://www.youtube.com/watch?v=Kkm8x6Zp-14&feature=related


Charles Darwin never said, "Survival of the Fittest."
Someone else did. I can't remember who, because he was not important. All I know is someone with a time machine needs to go back in time and bitch slap him.

Q:What did one set of genes say to the other set? A:"Like, Oh my God, you are so, like, random!"

 

This website presents an example of natural selection:

http://evolution.berkeley.edu/evolibrary/article/evo_25

Yet does not even define natural selection or explain what it exactly is!

According to their other page:

http://evolution.berkeley.edu/evolibrary/article/evo_32

So natural selection is mindless, mechanistic and has no goals but it is still not random ?

 

Darwin took "Survival of the fittest" off Herbert Spencer. In 1872 in the last edition of his book The Origin of Species he came to the conclusion that "natural selection" and "survival of the fittest" were the same thing. Chapter 4 of his book was titled "Natural Selection, or the Survival of the Fittest" in this chapter Darwin wrote that "survival of the fittest" is a "more accurate" definition of natural selection.

So natural selection is not random becuase organisms choose who they reproduce with whilst others die before reproducing. :shrug: Doesnt explain anything about evolution.

 

Clue me in here but who claimed it is not random... and the word "Random" needs to be defined for this context.

Random mutations, in this context, applies. It is "random." At least from our perspective.

Selective breeding is based on what traits a potential mate likes or dislikes. That is not random in this context.
If the traits are flawed enough that organisms have difficulty surviving to breeding age, that can be termed in this context as random, due to random mutations and events.

Ask yourself: Is it difficult to understand or are you resistant to understanding it?

Mazulu has a preference that he's able to tie in spiritual beliefs to science.

I will be very blunt- even some biologists and atheists may not like this statement- but it's how it is:
Evolution and Spiritual beliefs/Creation cannot be reconciled.
They stand apart. They cannot agree. It's just the way it is.

If a person cannot stand to leave them unreconciled, they are left with removing God to being active at the time of the Big Bang and inactive after that- or deliberately creating a clever, billions of years deception of making it look like he's not in existence while sending prophets to claim that he is in questionable desert scribblings.
Both notions are too insane to bother with trying to accept for a rational person.

 

It says so on most websites

http://www.pbs.org/wgbh/evolution/library/faq/cat01.html

I am still not getting why natural selection is not random.

If mutations are random like most scientists claim they are, then why isn't natural selection as well?

That is offtopic slightly for this thread, but note how natural selection was invented by a creationist.

 

Why would it need to be? Evolution has randomness, but think about this:
There's randomness in your daily life. How much of what happens to you is due to random events (Flat tire) and how much by choice?
Just because one part is random doesn't mean all must be. Just because some is not random doesn't mean all cannot be.

 

The following was written by Richard William Nelson:

Richard Dawkins has written that natural selection is not random.

Jerry Fodor and Massimo Piattelli-Palmarini, in their new book entitled What Darwin Got Wrong, delivers a stunning exposé on the Dawkins’s inane assertion that 1) natural selection is a logical theory, and 2) natural selection is nonrandom.

 

darryl

Is the result of moving the handle of a car jack random? No. Even if every movement of the jack handle is completely random, the only movements that have any effect are the one's that cause the jack to go up a notch(not random).

In evolution the random motions of the handle are the variations in the traits(from mutations and other causes), they are random. But the only variations that survive are those that give the lifeform a competitive advantage to reproduce, all the other variations dissappear from the gene pool. Even slight competitive advantages insure that those genes become more prevalent in the gene pool. That's Natural Selection and it is not random.

Sometimes sexual selection(choosing who to mate with)occurs, but it often leads to evolutionary cul-de-sacs like the Peacock, primed to be removed from competition sooner rather than later. But this is a result of intellectual evolution and behavior which, much like selective breeding by man, uses the evolutionary mechanisms toward self selected goals(pretty and otherwise useless tail feathers). Intellect can override or direct evolution but that is not the "Natural Selection" we are talking about here.

Yes.

Darwin was actually studying for the clergy, but it seems mainly because he could work indoors with no heavy lifting involved and continue his scientific investigations. But whatever he believed before his trip on the Beagle, what he found convinced him otherwise. If you make the same investigation honestly, with an open mind, you can come to no other conclusion than that Evolution has occurred throughout the history of life on Earth. Creatures that existed one hundred million years ago no longer exist, creatures alive today did not exist then(OK, there were sharks and aligators, but no monkeys). And Natural Selection is what drives evolution, often by hundreds or thousands or even millions of creatures dying for every one that survives to reproduce. Natural Selection is driven by nothing but survival to reproduce, whether you survive is determined by how well the traits that your DNA gives you meet the conditions you find yourself in. If you survive to reproduce you have been "Naturally Selected", if you don't, you are dirt(or food for other creatures).

Grumpy

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Natural selection describes how the circumstances of nature combine with the fitness of the individual or the gene(s) and results in variable survival rates. Perhaps the birds with the larger beaks are able to project their DNA forward in time because the larger beak allows them to take advantage of a particular food source. So, the DNA that results in large beaks becomes more frequent in the gene pool, and it can be said that the species changes just that small degree. The accumulation of these small changes results in what we call evolution.

 

Yeah, let's be honest about what different means.

So, according to you if each authority does not use a formulaic phrase that matches verbatim what every other authority uses then they are different.

That's the honesty of propaganda. Obviously, just like learning and understanding science, learning and understanding language requires a slight degree of sophistication. In this case, let's assume a high-school level.

Each and every one of your frenetically searched sources is saying the same thing. If you can't see that then maybe you need help in Science and English.

All you are doing is manufacturing a controversy which does not exist, simply by using tactics of propaganda. If you were attempting to argue from a position of evidence, then you would simply bring the evidence and the conversation would be about evidence, which is the larger goal of the forum, at least as far as it serves as a platform of mutual edification and as a myth-buster.

However in this case, I would have to say: "busted".

 

You see the bird eating the green bug? It was selected by its color and eaten so it will not reproduce. I chose this specifically for you since you have a problem with words.

The green bug was eaten because it was noticed by its color. What does any of what you just said have to do with that?

 

So?

Yes and a raft of experts have also condemned Jerry Fodor and Massimo Piattelli-Palmarini as I mentioned before.

So far you have people in philosophy, behavioral science and pharmacology. Do you think there's a reason why no biologists are represented here? As you trot out your argument from a position of authority, keep in mind that you are still evading the central issue which is evidence. Words and ideas are easily distorted. Evidence speaks for itself. The bird eats the visible bug. Now all you need to do is show that the bird eats randomly and we can move on.