Males dim mentally after generations without competitors
The demands of outmaneuvering other guys when courting may help male fruit flies stay mentally sharp.
After more than 100 generations in the lab without male competition, male fruit flies didn’t do so well in a standard test of learning, reports evolutionary biologist Brian Hollis of the University of Lausanne in Switzerland.
The male Drosophila melanogaster still courted with normal enthusiasm and success when alone with a female. But in groups, the long-sheltered males lagged when competing with another strain of males in siring young. A series of other tests suggests that the competition-free populations faltered not because of physical weakness but because they had lost some of their smarts for coping with complex mating crowds. Male competition and other forms of sexual selection may be unappreciated evolutionary forces for maintaining a species’ smarts, Hollis and Tadeusz Kawecki of Lausanne propose February 26 in the