Evolution: a different view with loss of traits; not Behe (Introduction)

by David Turell , Wednesday, September 16, 2020, 19:23 (1528 days ago) @ dhw

DAVID: Behe is presenting a reason for species modification.

dhw: Species modification is not speciation! The bear example shows that, just like the article we have been discussing, this theory relates to ADAPTATION, which you agree “goes on either by deletion or gene modification”. It makes perfect sense that when a species adapts to different conditions, certain genes will become unnecessary. But then I would argue that the changes (why “advances”?) do not RESULT from loss of genes: loss of genes is the result of the changes, because they are no longer needed. Let me stress again that I’m not arguing here with Behe. I’m arguing with the muddled case you have presented.

DAVID: Behe calls his finding "Darwin devolves" and believes his analysis may well tell us how speciation occurs. What I presented is not muddled, to counter to one of your favorite theories straight out of Neo-Darwin.

dhw: You began by telling us that evolutionary “advances always result from loss of genes”, which I challenged. This was diluted into Behe presents “a reason for species modification” (which sounds to me like changes within the same species, and not speciation), and now you tell me Behe believes this “may well tell us” how speciation occurs. You keep modifying your interpretation of Behe, and changing your objections to my own proposal: first it was “no new genes” (but there are), then it was random mutations (irrelevant to my proposal), and then it was that evolution is no longer on-going, which is irrelevant to the cause of speciation. Here comes the next objection:

DAVID: Currently the human gene study tells us there are many mutations in existing genes and humans are still humans. Where is your theory?

dhw: What do you mean “where is your theory”? My theory, proposed in response to your version of Behe’s theory, concerns speciation. But mutations within existing species which lead to variations within that existing species are irrelevant to the subject of speciation! Has the human gene study now proved that no species in the history of life has ever contained new genes? My theory is that speciation entails the production of new genes (you now agree they exist), new uses for old genes (do you disagree?), and the discarding of genes that are no longer of any use. Now please tell me which of these proposals you object to, and why you think that speciation can only be achieved by loss of genes.

Because Behe's entire book is a recitation of gene loss in several different branches of life: woolly mammoths, Yersinia pestis, African cichlid, dog breeding, etc. His whole point is change by DNA loss. And of course the necessity for intelligent design. New genes may appear but how much are they expressed and to what degree? Behe never shows changes due to new genes. But of course that is not his point. I am not aware of any study that shows new genes producing anything of importance. Behe even shows the Lenski E. coli study has not produced anything of great importance, just minor changes in the metabolism of the same species.