Whoa! Whoa! dhw take notice!!! (The limitations of science)

by David Turell , Saturday, April 19, 2014, 06:47 (3870 days ago) @ xeno6696

Matt: Let me focus here: 
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> David: Natural selection never creates variety.
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> Yes it does: It is responsible for forcing organisms to adapt. That means precisely that variety doesn't come into tangible fruition, without selection. And my analogy was absolutely perfect: you agreed to it exactly... but didn't!-That's because I think you look at it backwards. The genome is built to produce experimentation. Natural selection does not force genetic drift or random mutation. It does cause epigenetic attempts at new accommodations. But it is the genome that methylates DNA and the adaptations are juddged by competition in nature.
 
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> Matt: But those changes rarely result in observable phenotypes. (I'm leaving room for "simple" changes such as fur color/eye colour/size variations etc.)
 
 You are trying to bring in speciation with the phenotype proposal. You forget the famous experiment with Reznick's guppies. There whole populations changed size. I know you tried to exclude size, but we are not discussing speciation, just adaptation. We have no idea how speciation occurs, despite Darwin's theory.
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> Matt:But if an event never happens that puts pressure against those alleles, evolution does not happen! This echoes a previous post, where I stated to prove that epigenetics is a stronger source of evolutionary change, you needed to be able to demonstrate that an organism exhibits enough of a change as to be called a different species, without the presence of selective pressure. -Yes, natural selection applies selective pressure among all the varieties produced by an organism, and epigenetics appears to be the main adaptive mechanism that is applied, but it is the variety produced by the organism from which natural selection results in surviving choices, all adaptations, not new species. I agree that challenges in nature force the genome to create adaptations, but natural selection is only an arbiter or judging system. Perhaps we should define what you think the term natural selection means. I think it is the result of competition between organisms or competition with natural events and forces.
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> Matt:Maybe a football (soccer) analogy is in order: Natural selection is the goalie. It doesn't matter at all what happens on the other side of the field, except in the ultra-rare instances when the ball gets past the goalie.-That I can accept as an analogy. Note the goalie sits on his hands until the ball finally starts to come his way. All of the preliminary action is elsewhere. His stopping the ball or missing it is a final step.