From William Basenerand John Sanford at The Skeptical Zone:

Joe Felsenstein and Michael Lynch (JF and ML) wrote a blog post, “Does Basener and Sanford’s model of mutation vs selection show that deleterious mutations are unstoppable?” Their post is thoughtful and we are glad to continue the dialogue. This is the first part of a response to their post, focusing on the impact of R. A. Fisher’s work.

R. A. Fisher was one of the three founders of population genetics, and is considered by many to be the first and primary founder. His Fundamental Theorem of Natural Selection contributed significantly to a “revival of Darwinism” (see Koonin quote above and Wikipedia). His theorem has been considered by many a significant and rigorous support for the Neo-Darwinian Theory (see quotes above).

Our paper shows that Fisher’s corollary is clearly false, and that he misunderstood the implications of his own theorem. He incorrectly believed that his theorem was a mathematical proof that showed that natural selection plus mutation will necessarily and always increase fitness. He also believed his theorem was on a par with a natural law (such as entropic dissipation and the second law of thermodynamics). Because Fisher did not understand the actual fitness distribution of new mutations, his belief in the application of his “fundamental theorem of natural selection” was fundamentally and profoundly wrong – having little correspondence to biological reality. Therefore, we have reformulated Fisher’s model and have corrected his errors, thereby have established a new theorem that better describes biological reality, and allows for the specification of those key variables that will determine whether fitness will increase or decrease.More.

But whether Fisher’s thesis is false or true does not really matter in today’s science culture. Darwinism is now a religion of the semi-educated classes. Fisher’s theorem can survive as a nuke tweet [!].

Real science will increasingly be elsewhere, skirting disapproval.

*See also:* On Basener and Sanford’s paper falsifying Fisher’s Darwinism theorem: It will be no small thing to make reality matter again.