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Replying to post 1180 by Neatras]
Because I already debunked this bogus claim by Kimura before. People are free to believe or not believe the FACTS I give.
Is man presently degenerating genetically?
It would seem so, according the papers by Muller, Neal, Kondrashov, Nachman/Crowell, Walker/Keightley, Crow, Lynch et al., Howell, Loewe and also myself. Scott suggests this is foolishness and dismisses the Crow paper (1–2% fitness decline per generation). But Kondrashov, an evolutionist who is an expert on this subject, has advised me that virtually all the human geneticists he knows agree that man is degenerating genetically. The most definitive findings were published in 2010 in the Proceedings of the National Academy of Science by Lynch.4 That paper indicates human fitness is declining at 3–5% per generation. I personally feel the average mutational effect on fitness is much more subtle than Lynch does—so I think the rate of human degeneration is much slower than he suggests—but we at least agree that fitness is going down, not up. Can Scott find any qualified geneticist who asserts man is NOT now degenerating genetically? There is really no debate on current human genetic degeneration.
virtually all the human geneticists he knows agree that man is degenerating genetically
Is there a theoretical problem associated with continuously growing genetic load due to subtle un-selectable deleterious mutations? Yes, according to Muller, Kondrashov, Loewe, and many others. Population geneticists all seem to acknowledge the fact that a large fraction of deleterious mutations are too subtle to be effectively selected away. The question is, what is that fraction? At what point does the fitness effect of a deleterious mutation become too small to be selected away? I have been studying this for about 7 years. Our numerical simulations indicate that for higher organisms, up to 90% of all deleterious mutations should be un-selectable (Chase W. Nelson and John C. Sanford, 2013, Computational Evolution Experiments Reveal a Net Loss of Genetic Information Despite Selection, Biological Information: New Perspectives pp. 338–368;
https://doi.org/10.1142/9789814508728_0014).
What is Dr. Ohta’s view on genetic degeneration?
Dr. Tomoko Ohta was a key student of Kimura, and published extensively with Kimura. Dr Ohta came to be known as the ‘Queen of Population Genetics’, and is now an honorary member of the American Academy of Arts and Sciences, and an associate of the National Academy of Sciences, USA. She is the world’s authority on the topic of near-neutral mutations. One of my co-authors went to Japan to spend several days discussing with her a manuscript in which we used numerical simulation to clearly demonstrate that near-neutral deleterious mutations generally escape selective removal and lead to continuous and linear accumulation of genetic damage. She acknowledged that our numerical simulations appeared to be valid, and that our conclusions appeared to be valid. This clearly reflects a profound evolutionary paradox (it is the same paradox Kondrashov addressed in his paper “why have we not died 100 times over?�5). When asked about synergistic epistasis, she immediately acknowledged that synergistic epistasis should make the problem worse, not better, just as I argue in my book. Using numerical simulations, we have confirmed that synergistic epistasis fails to slow mutation accumulation and accelerates genetic decline (Can Synergistic Epistasis Halt Mutation Accumulation? Results from Numerical Simulation; doi.org/10.1142/9789814508728_0013).
