| Citation | Parker has made distinguished contributions to evolutionary biology, in particular to frequency-dependency in the evolution of animal behaviour and sexuality. He made and later developed the fundamental discoveries concerning the evolutionary mechanism for the origin and maintenance of the two sexes. He also pioneered the concept of sperm competition (the evolutionary consequences of competition between sperm from different males in fertilizing ova), which has subsequently developed into an important field of study in its own right. His research on mate choice in the fly Scatophaga is classic. He constructed and tested a series of detailed mathematical models of male behaviour based on the concept of optimisation at the individual level. His later work has developed in important ways Maynard Smith's approach to the theoretical modelling of evolutionary games in behavioural conflicts, animal distributions, and aspects of reproductive and life history strategies. |