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

by dhw, Tuesday, September 15, 2020, 12:01 (15 days ago) @ David Turell

DAVID: You are struggling with the concept presented by Behe. He starts his book by presenting the polar bear who is closely related to the grizzly and the black bears, and evolved away by degrading two key genes. The field is changing. Time will tell you to support Behe or not.

dhw: I would not regard differences between bears as proof that speciation in the broad sense (e.g. bears versus cats) is always caused by loss of genes. These bears live in different environments, which suggests to me adaptation, with a loss of genes that would not be needed for their environment. But if your interpretation of Behe’s theory is correct, and he says all speciation results from loss of genes, yes, let’s see whether time and science support him.

DAVID: The bears are just one example. I can't repeat the entire book here. I gave one example of many.

dhw: Not a very good example, then, but I’m not arguing with Behe. I'm arguing with you. Let’s wait and see whether scientists all agree that evolutionary “advances always result from loss of genes”.

dhw: Meanwhile, I have asked you repeatedly why you have rejected my proposal, having withdrawn your original objection that there were no new genes. Here it is again, to refresh your memory:
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: New mutations occur by chance under Darwinian science. […]

dhw: I have not mentioned and in fact oppose the concept of chance mutations! That is a total digression. Please tell me what is wrong with what I have written.

DAVID: The human genome study, about thirty years old, shows that all of us, unchanged, are filled with genes with mutations making each of us slightly different.

Irrelevant to our subject of speciation. (Thirty years old? Then we’d better forget your ridiculous suggestion that studies of “new genes” don’t count because they were written seven years ago.)

DAVID: Our translation and transmission of instructions is tightly controlled as in this entry four days ago:
"Genome complexity: DNA transcription and translation II (Introduction)
by David Turell @, Friday, September 11, 2020, 21:00 (3 days ago)"
and this explains why the mutations mean nothing. I don't know how your 'theory' relates to the major issue of how speciation occurs. The study doesn't seem to show we have new genes.

You have already agreed that new genes exist. I have proposed that speciation is accompanied by new genes or old genes taking on new roles. That is how my ‘theory’ relates to speciation! According to your version of Behe, evolutionary “advances always result from loss of genes”, and “I view evolution as over and Behe's probable explanation of speciation as a very cogent avenue for a new theory of speciation.” I assumed that meant speciation, but now you suddenly change your terminology:

DAVID: Behe is presenting a reason for species modification.

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: I agree only that a new gene theoretically might appear and its expression will be tightly controlled.

Yes, of course. There would be no point in a new gene appearing if it didn’t have a particular function.

DAVID: I totally disagree that evolution is ongoing. God has stopped producing it having reached His goal of humans. […]

That is not the point of our discussion. You objected to my ‘theory’ because you said there was no such thing as new genes. Objection withdrawn. Then you objected because it relied on random mutations, but my theory doesn’t even mention random mutations, and I do not believe in them as the driving force of evolution. Now you object because you have a theory that evolution is finished. OK, then change my tense to “was”, and please tell me at last what you object to.


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