  This is a review of William Feller's important contributions to mathematical
biology. The seminal paper [Feller1951] "Diffusion processes in genetics" was
particularly influential on the development of stochastic processes at the
interface to evolutionary biology, and interesting ideas in this direction
(including a first characterization of what is nowadays known as "Feller's
branching diffusion") already shaped up in the paper [Feller 1939] (written in
German) "The foundations of a probabistic treatment of Volterra's theory of the
struggle for life". Feller's article "On fitness and the cost of natural
selection" [Feller 1967] contains a critical analysis of the concept of
"genetic load".
