ABSTRACT:
Human populations exhibit a variety of eye color phenotypes, with Europeans exhibiting more diversity than others. A variety of selective mechanisms to explain this pattern have been proposed; these include a general preference for blue eyes, parental imprinting effects inbreeding avoidance behaviors, paternity assurance preferences and frequency dependent selection favoring rare phenotypes (termed negative FdSs). Here we show, using an ethnically diverse study population asked to rate the attractiveness of faces of Caucasian members of the opposite sex in which the eye color frequencies were manipulated, strong support for negative FdSs exhibited by white females of European ancestry. Our data shows no support for FdSs in females of other ethnicities or males and a lack of support for any of the other models listed above. These results are consistent with a model of human evolution in which a history of negative FdSs by European females, but not males, is responsible for the high degree of eye color diversity seen in modern Europeans.
