Russell and Cecy
I'm about a third of the way through "Nature’s Oracle: The Life and Work of W D Hamilton" by sociologist Ullica Segerstrale - (Hamilton: 1 August 1936 – 7 March 2000). Hamilton put the theory of evolution on a sound footing by his post-WW2 development of population genetics. The biography is fascinating about Hamilton's character (he sounds Asperger's to me) but is science-lite.
Population genetics is, however, fascinating; here is what Wikipedia has to say about it.
"Population genetics is the study of allele frequency distribution and change under the influence of the four main evolutionary processes: natural selection, genetic drift, mutation and gene flow. It also takes into account the factors of recombination, population subdivision and population structure. It attempts to explain such phenomena as adaptation and speciation."
I'm looking for a book at the right level - not too populist, not too advanced.