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

by dhw, Monday, September 14, 2020, 13:57 (1291 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.

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dhw: Meanwhile, I have asked you repeatedly why you have rejected my proposal, having withdrawn your original objection that there were no new genes.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:

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: New mutations occur by chance under Darwinian science. That is where you are starting. Have you forgotten that only a few new mutations are helpful, many are deleterious and the majority are neutral? Human DNA in everyone studied is filled with neutral mutations. I view evolution as over and Behe's probable explanation of speciation as a very cogent avenue for a new theory of speciation. But, yes, adaptation goes on either by deletion or gene modification.

I have not mentioned and in fact oppose the concept of chance mutations! That is a total digression. You have acknowledged the existence of new genes, whatever the source, and I have proposed that evolution is an on-going process which entails the acquisition of new genes or new functions for old genes, with loss of unwanted genes. Initially you objected because you didn’t accept that new genes existed. You withdrew that objection and have now rejected my proposal by inserting random mutations into it. Please tell me what is wrong with what I have written.


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