Cognitively Driven Co-Option and the Evolution of Complex Sexual Displays in Bowerbirds

Sexual selection theory has not been able to resolve the relative importance of major models. Evidence showing a major role for cognition in mate choice has received little consideration and could help settle this issue. Recent studies of a variety of species now suggest cognitive abilities may be important generally in affecting their behavior. Here we propose that models including a cognitive component directing co-option can explain the relatively rapid evolution of complex behavioral displays. Coincidentally, use of cognition should enhance female ability to make adaptive mate choice decisions. In our studies of bowerbirds, many behaviors and processes associated with mate choice and sexual competition indicate an important role for co-option and cognition consistent with the above model. While bowerbirds may be extreme in the complexity of their display, this work suggest that displays may often be co-opted from preexisting male traits in other species.