Unraveling Fisher's mysteries

Haldane’s Sieve has a great post by James Lee giving context to a new preprint from him and Carson Chow: “Our paper: The causal meaning of Fishers average effect”.

This paradox continued to bother me over the next several years. Soon after my daughter was born, I indulged one of those wild impulses that strike the sleepless: I emailed my questions regarding this matter to Anthony W. F. Edwards, the last student of the great Fisher himself. Anthony very generously sent me some of his unpublished work and also his correspondence with Falconer about the very article that had spurred my thoughts. This correspondence spanned a period of more than 20 years, and it provided a very poignant portrait of Douglas Falconer as a scientist (Hill and Mackay, 2004). I did not immediately find the answers to my questions in the materials that Anthony sent to me, but they set me on the path toward finding the answers. These are presented in the paper, which will shortly appear in Genetics Research.

Fisher invented a lot of statistical concepts, many of which are used universally by everybody, even far outside genetics. But he also invented some that nobody else has been able to understand. The “average effect” of an allele is one of them. The concept was central in the development of his “Fundamental Theorem” of natural selection, but why it works is not obvious. Lee’s post does a great job explaining why this was an interesting and useful project to undertake.