b. 1944
John H. Gillespie is a population geneticist and philosopher of biology, best known for his theoretical work on molecular evolution and the genetic basis of natural selection. He has challenged orthodox neo-Darwinian assumptions by arguing that genetic drift and episodic selection play a larger role in molecular evolution than the Modern Synthesis acknowledges. His work occupies the boundary between formal evolutionary theory and the philosophy of science.
Developed the 'SAS-CFF' model challenging the neutral theory of molecular evolution
Argued that natural selection theory requires reexamination as a cognitive or explanatory framework in science
Authored 'The Causes of Molecular Evolution' (1991), a foundational text in molecular population genetics
Contributed formal models distinguishing the roles of drift versus selection at the molecular level
Wrote 'Population Genetics: A Concise Guide', widely used in graduate education