Wynne-Edwards was best known for espousing a form of
group selection that operates at the level of the species, most notably in his 1962 book,
Animal Dispersion in Relation to Social Behaviour. In it, he argued that many behaviors evolved for the good of groups of the species as a whole, rather than at a lower level of organization. For example, he argued that species have adaptive population-regulatory mechanisms. His arguments were vigorously criticized by
George C. Williams in his
Adaptation and Natural Selection, a debate summarized by
Richard Dawkins in
The Selfish Gene.
David Sloan Wilson and
E. O. Wilson characterised Wynne-Edwards' theory "naive group selection", since it did not use quantitative models. But they also provided examples of rigorous models that can predict his field observations. Among the mechanisms that Wynne-Edwards proposed was population regulation, based on the communication of population density by what he called epideictic displays, in which individuals advertised their genitals. If a population was becoming too dense, such displays would result in reduced breeding across the population, contrary to Darwinian
natural selection but in line with Wynne-Edwards's group selection. The mechanism has never been demonstrated unequivocally. ==Fellow of the Royal Society==