Gradualism in Evolution not supported by genome studies (Agnosticism)

by David Turell , Saturday, October 10, 2020, 16:08 (1287 days ago) @ dhw

dhw: I would like to make a slight change to my proposal, in direct opposition to the theory I have been objecting to: Speciation is caused by the acquisition of new genes AND new functions for old genes, and is ACCOMPANIED by loss of unwanted genes etc.
If you now accept my revised proposal, I think we can close this thread.

DAVID: I do not agree fully with the bold above. Loss of genes appears to be one of causes of speciation along with a restructuring of expression of genes and may include new genes added. But based on Behe, some speciation changes are just deletion.

dhw: A restructuring of expression of genes is what I call new functions for old genes. This whole discussion began with my disputing the claim that “advances always result from loss of genes”. I only know Behe’s theory from what you tell me, so I don’t know if his examples are minor variations or totally new species. I remember you picking on the example of the polar bear lacking two genes found in the grizzly and the brown bear. I wouldn’t call this an advance. They are all bears, but they live in different conditions, and had to adapt accordingly. The obvious inference is that genes which operate in a warm climate won’t be of any use in a cold climate. I can’t see the logic in the argument that losing useless genes will create a new fur coat. But I can only discuss the points you reproduce here. Since we do in fact call these different bears different species, perhaps we shouldn’t be using the word “speciation” at all and should stick to the term used in the latest article: “major evolutionary transitions”, which I would equate with innovation and which, you will remember, occur when “vast numbers of existing genes are jettisoned and replaced by entirely different ones”. But I would also expect loss of genes as a RESULT of minor transitions and not as the cause.

Behe is a pioneer in theory just like Shapiro. He does use the polar bear as a prime example of species change. You are correct. it is really a massive adaptation to specific environment. He also discusses the mammoth and its DNA differences from elephants, in which it is found between 500-800 genes were degraded. His book is filled with such examples of adaptation by gene degradation. His prime thought early in the book to quote is: "Darwin's mechanism works chiefly by squandering genetic information for short-term gain." By this he means adaptation which aids survival "by damaging or breaking genes." (pages 37-38) By no means does he says he is positive full speciation in evolution is the cause of speciation, but he feels he is offering strong evidence in a 342 page book filled with adaptive examples. All dog varieties are due to damaged/degraded genes, but following your thought they are still really mostly wolves, as shepherd/wolves exist. Susan and I have been to a local breeding/rescue ranch out of curiosity..