Evolutionary Biology
T. Madsen, R. Shine, J. Loman, T. Hakansson, "Why do female adders copulate so frequently?" Nature, 355:440-1, 1992.
Richard Shine (University of Sydney, Australia): "According to Charles Darwin's theory of natural selection, individual organisms should behave in ways that maximize their reproductive output. This simple notion makes an immediate prediction about sexual behavior, at least for species in which males don't take care of their offspring. We would expect that males in such species would be very willing to mate with many different females, because any additional matings would enhance the male's evolutionary fitness. However, a female seems less likely to benefit (in evolutionary terms) from such `promiscuity.' Because mating with more than one mate will not increase the number of offspring a female can produce, we might expect that females would generally be reluctant to mate with more than one male. But observations of many species falsify...