Hans Ellegren and Ben Sheldon, two biologists at the University of Uppsala, in Sweden, and their colleagues, have demonstrated that female collared flycatchers do indeed adjust the sex ratios of their broods according to the sexiness of their mates.
Genetic analysis led by a team at Sweden's UppsalaUniversity found that the woman closely resembled modern-day Southern Europeans and had many genetic differences from three hunter-gatherers living at the same time in Sweden and buried nearby.