PLANT AND ANIMAL SCIENCES
BY FRANCISCO J. AYALA
Department of Ecology and Evolutionary
University of California, Irvine
" The gene that switches embryonic development into the male rather than the female pathway is located on the short arm of the Y chromosome in humans as well as in mice. How this gene exerts its effects is still a mystery.
A. McLaren, “Sex determination in mammals,” Trends in Genetics, 4 (6), 153-7, June 1988.
" Many insect species carry volatile compounds in the cuticle that function as aphrodisiacs or antiaphrodisiacs. Contact during mating results in a mutual exchange of compounds that are sex specific. Often, the female compounds stimulate the males that acquire them to court, but the male compounds decrease the attractiveness of females after mating. In Drosophila melanogaster, the compounds (hydrocarbons) exchanged during mating decrease the attractiveness of both males and females to members of the...