Sexual infidelity: the development of evolutionary explanations

A long-term study on the genetic inheritance of sexual behavior in the zebra finch conducted at the MPIO casts new light on the causes of sexual infidelity. Previously, it was always assumed that female infidelity could only evolve if it was beneficial to females. The present study, however, shows that this is not necessarily the case. Since male and female infidelity appear to be controlled by largely the same genes, the existence of female infidelity may simply be explained by the fact that the responsible genetic variants were positively selected in the male ancestors.