population genetics
Charlesworth B & Charlesworth D 2016 Population genetics from 1966 to 2016. Heredity, in press.
doi:10.1038/hdy.2016.55
- DNA sequence variation
- the pioneering work was done by Kreitman (1983), working in the Lewontin lab
- applications of diffusion equations
- in the late 1960s and early 1970s, Motoo Kimura and Tomoko Ohta spearheaded the application of diffusion equations, first introduced into population genetics by Fisher (1922), to theories of molecular evolution and variation
- a famous early result is that the rate of neutral sequence substitutions between species is equal to the neutral mutation rate (Kimura, 1968), providing an explanation for the 'molecular clock' proposed from studies of sequence evolution
- this result had already been derived by Wright (1938), but had received little attention in the absence of data to which it could be applied
- another important contribution was the introduction of the 'infinite sites' model, appropriate for mutations at individual nucleotide sites that occur so rarely that a given site segregates for at most two variants (Kimura, 1969)
- this model was originally formulated by Fisher (1930a), before any knowledge of the role of DNA as the genetic material
- for analyses of DNA sequence variation, the infinite sites model largely replaced the earlier 'infinite alleles' model (Kimura and Crow, 1964), that describes allelic variation of whole genes rather than individual nucleotide sites
- LD and selection
- models of selection at two or more linked loci had already been developed (see, for example, Kimura, 1956)
- this continued into the 1970s, mainly in the hands of Stanford University population geneticists
- this work was largely concerned with the problem of the nature of the equilibria generated by the interaction between epistatic selection and recombination
