Sex wars drive evolution

Males continually evolve novel adaptations to entice females to mate with them rather than with other males, and females continually evolve novel strategies to resist these manipulations. It is suggested that this sexual conflict could be the strongest driver of speciation, but the supporting evidence has been limited. In the June 26 Nature, Oliver Y. Martin and colleagues at the Zoological Museum of the University of Zürich, show that increased sexual conflict caused a rapid increase in behavioral reproductive isolation, especially in larger, high-density populations, confirming the importance of conflict as a driving force in evolution (Nature, 423:979-982, June 26, 2003).

Martin et al. examined replicating fly populations of the dung fly Sepsis cynipsea with varying levels of sexual conflict. They observed that in larger, denser populations with more sexual conflict there was a very rapid evolution of female willingness to mate and of male traits...