Natural Selection.

Philosophy Forums Science, Technology, and Math
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Introduction.

I have been making a small study of evolution lately. This thread is meant as a primer both for my readers and for myself (my readers may well know more about the subject than I, after all).

Evolution basically consists of two mechanisms: ‘natural selection’ and genetic drift. I’m not really interested in genetic drift: it is very simple, and only helps to make evolution complex in combination with ‘natural selection’ and other factors (e.g., gene flow). I’m not really interested in such ‘chaos evolution’, either; my interest does not lie in the direction of the actual evolutionary process as it goes on in nature, but in ‘natural selection’ pure and simple.

1. ‘Natural selection’ itself.

The reason I write ‘natural selection’ within quotation marks is that it falsely suggests (perhaps not by itself but due to the common misconceptions about it) that there is such a thing as an ‘agent’ called Nature that actively ‘selects’ certain genotypes. Nature thus personified is an anthropomorphism. There is no such thing as a natural agent!

To the contrary: natural selection is a mechanism. Richard Dawkins has said: “Darwinian natural selection is so stunningly elegant because it solves the problem of explaining complexity in terms of nothing but simplicity.” [Dawkins, An atheist’s call to arms (7:02-7:12).] Now the explanation of complexity by natural selection is indeed ‘elegant’, as opposed to “crude”, in that it does the opposite of postulating an even more complex being who has supposedly ‘created’ nature in all its complexity. It does not demand faith in that postulation, or in the supposed revelations of the truth of that postulation; the explanation by natural selection bases itself solely on reason. But “elegant”, though also perfectly fitted to Dawkins’ typically English civility, is ironically a very bad word to use in relation to natural selection itself. For “elegant” derives from the Latin verb eligere, “to select with care, to choose”. As with the phrase “natural selection”, however, there is no agent in nature that ‘cares’ about what is selected and what is not. It is a mechanism: the crudest possible thing to the human mind.

Fact 1: Some genetically based traits further the fitness (ability to reproduce) of their possessor more than others.
Fact 2: Traits with genetic bases are hereditary.
Consequence: Genetically based traits that further the fitness of their possessor more are more likely to be reproduced than those that do so less.

2. ‘Survival of the fittest’.

Another concept of natural selection about which common misconceptions exist is the ‘survival of the fittest’. Really, this is a truism: a case of A=A. For all “fit” means in the context of evolution is “capable of reproducing”, and what “survival” means in this context is the survival of the genotype over generations. So “survival of the fittest” means “reproduction of the most capable of reproducing”.—

3. Adaptation.

Another such concept is adaptation. This does not mean the adaptation of the individual, but of the species. And it is not active, of course (see the remarks on ‘agents’ above), but passive: the species adapts through natural selection.

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Natural selection is based on enviroment

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Yes, that’s right. Fitness is not an absolute quality. It means “ability to reproduce in the environment in question”.

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yes

adaption

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“Adaptation”, in the context of evolution, is the adaptation of the species, not the individual, to the environment.

Say we have four white rabbits and four brown rabbits in a brown environment. The white rabbits will have inferior camouflage and will therefore be more likely to be eaten by predators before they can reproduce. So in the next generation, we may have only two white rabbits and six brown rabbits. And in the next generation, one to seven.

B: 4 —> 6 —> 7
W:4 —> 2 —> 1

Thus the ‘species’ adapts to the brown environment by becoming more brown.

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“Adaptation”, in the context of evolution, is the adaptation of the species, not the individual, to the environment.

Say we have four white rabbits and four brown rabbits in a brown environment. The white rabbits will have inferior camouflage and will therefore be more likely to be eaten by predators before they can reproduce. So in the next generation, we may have only two white rabbits and six brown rabbits. And in the next generation, one to seven.

B: 4 —> 6 —> 7
W:4 —> 2 —> 1
[/quote]

yes

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Reminds me about brown moth and black moth. When England Industrial era happens…the brown moths were easily spotted by predator and being eat up…until left most of black moth. Those black moths pass down their genes to the next generation… and they (new generation survive). They adapted and after they enforce ruling about reducing air pollution, increase air quality…the black moths were easily spotted by predator and being eaten up…until left most of the brown moths.