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

by dhw, Saturday, September 12, 2020, 12:51 (1533 days ago) @ David Turell

dhw: I suggest that the process is on-going, with a constant acquisition of new genes (or new functions for old genes) and loss of unwanted genes. Natural selection merely decides which genes are necessary and which are not.[…]

DAVID: The acquisition of new genes in your statement now in red is not supported.

dhw: […] why is this thread headed “not Behe”?

DAVID: To point out people other than Behe are making the same observation.

dhw: So why is it a “different view” if, as you claim, it is now the accepted view?

DAVID: The start of being accepted at least for adaptations within species. Behe is about actual speciation.

So the article is different from Behe. Thank you.

DAVID: The point at issue is whether new species are due to new gene complexes appearing. Of course new genes appear, but in established species we follow with minor modification, if at all. This is a new issue with the field in flux. What I have found in the current literature is appearing to be supportive of Behe. The issue is how speciation occurs, not whether new genes appear.

dhw: If the issue is in flux, please don’t claim that articles written in 2013 have been discredited and that “advances always result from loss of genes”. According to the article you quoted, loss of genes accompanied adaptation. There was no mention of innovation or of speciation. And since your only objection to my proposal was that there was no support for the acquisition of new genes, and you have now withdrawn that objection, please explain why you continue to object to my proposal.

DAVID: 2013 articles reflect thinking at that period of time. We are talking about new analyses related to how new species might appear.

So are you now telling us that there is unanimity in the scientific world that new genes did not contribute to evolutionary advances, and everyone agrees that “advances ALWAYS result from loss of genes”? Ugh, I wonder what the whole scientific world will be agreeing on in 2027. This is getting silly.

DAVID: Remember the article I quoted had this headline: "By Losing Genes, Life Often Evolved More Complexity".

Yes, I remember. I pointed out to you that it said “often”, not always. And I pointed out to you that the article talked only of adaptation (as you admit above), not innovation and speciation.

DAVID: And what is found is disappearance of DNA. If loss of DNA results in beneficial adaptation within a species, it is easy to make a stretch, as you do in so many of our debates, to suggest that might be the way new species appear. Behe's book makes quite a case for it. At least accept that point.

I am happy to accept the point that loss of DNA accompanies adaptation, and to accept the “stretch”. I’m not convinced that loss of genes causes adaptation, let alone speciation, but I'd need to study all the arguments for and against before forming any opinion. A “stretch” and “might be” and “quite a case” are all welcome modifications of your earlier authoritative statements. Meanwhile, you rejected my proposal on the grounds that there were no new genes. You have withdrawn that objection, so once more, please tell me why you still reject my proposal.