Author:

Keywords:

Genetic genealogy, Population genetics, Y-chromosome, Extra-pair paternity, Surname

Abstract:

Although a human father invests heavily in his child, he cannot be certain that he is the biological parent in contrast to the mother. When the caring father is not the biological one, a so-called extra-pair paternity (EPP) event occurs. After decades of speculation and many false or biased claims of high EPP frequencies in human populations, which are still referred to in influential scientific literature, reliable data on contemporary populations has become commonly available as by-products of medical studies. Nonetheless, long-term trends in EPP frequencies are still controversial as current measurements may not reflect historical frequencies due to changes in social interactions and recently introduced factors such as contraceptive methods. As a solution, methods combining Y-chromosomal data with in-depth genealogies are now developed to estimate historical EPP rates. Several recent genetic genealogical studies calculated the average past EPP rate in Western and African populations over the last 500 years. The results revealed an overall low rate of cuckolded fathers in the range of 1-2% across contemporary as well as historical human societies. These frequencies estimated by genetic genealogy are, however, only yet a mean value which can still differ over time and space within a population due to evolutionary, cultural and socio-demographic factors. During this talk, new results on the spatio-temporal range of EPP rates before, during and after the demographic transition and industrialisation within Western Europe will be presented and discussed. Our findings suggest that the manifestation of sexual conflict in humans is strongly dependent on the social circumstances that modulate both the opportunities and the incentives for extra-pair copulations.