Theory is theory is a theory.
-Yours Truly
What Darwin Got Wrong
According to Darwin, traits of creatures are selected for their contribution to fitness [likelihood to survive]. But how do you distinguish a trait that is selected for from one that comes along with it? There are a lot of interesting structures in creatures that have nothing to do with fitness.
Some variants in selection are clearly environmental. If you can’t store water you’ll do worse in a dry environment than if you can. But suppose that having a high ability to carry a lot of water is correlated for genetic reasons with skin color. How do you decide which trait is selected for by environmental factors and which one is just attached to it? There isn’t anything in the Darwinist picture that allows you to answer that question.
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What the genetics has come to show is that traits are not independent, but complexly interconnected, and a lot of the effect that the environment has on an organism’s evolution depends on what organism it is.
Some variants in selection are clearly environmental. If you can’t store water you’ll do worse in a dry environment than if you can. But suppose that having a high ability to carry a lot of water is correlated for genetic reasons with skin color. How do you decide which trait is selected for by environmental factors and which one is just attached to it? There isn’t anything in the Darwinist picture that allows you to answer that question.
....
What the genetics has come to show is that traits are not independent, but complexly interconnected, and a lot of the effect that the environment has on an organism’s evolution depends on what organism it is.
Update: one should take care, as I haven't done above, to separate the phenomenon of common ancestry from the theory of the mechanisms by which evolutionary biological changes take place. It should go without saying, but still...