Saturday, August 30, 2008

Long term cultural selection for male dominance traits?

Male dominance rarely skews the frequency distribution of Y chromosome haplotypes in human populations
J. Stephen Lansing, Joseph C. Watkins, Brian Hallmark, Murray P. Cox, Tatiana M. Karafet, Herawati Sudoyo, and Michael F. Hammer
PNAS August 19, 2008 vol. 105 no. 33 11645-11650
Abstract: A central tenet of evolutionary social science holds that behaviors, such as those associated with social dominance, produce fitness effects that are subject to cultural selection. However, evidence for such selection is inconclusive because it is based on short-term statistical associations between behavior and fertility. Here, we show that the evolutionary effects of dominance at the population level can be detected using noncoding regions of DNA. Highly variable polymorphisms on the nonrecombining portion of the Y chromosome can be used to trace lines of descent from a common male ancestor. Thus, it is possible to test for the persistence of differential fertility among patrilines. We examine haplotype distributions defined by 12 short tandem repeats in a sample of 1269 men from 41 Indonesian communities and test for departures from neutral mutation-drift equilibrium based on the Ewens sampling formula. Our tests reject the neutral model in only 5 communities. Analysis and simulations show that we have sufficient power to detect such departures under varying demographic conditions, including founder effects, bottlenecks, and migration, and at varying levels of social dominance. We conclude that patrilines seldom are dominant for more than a few generations, and thus traits or behaviors that are strictly paternally inherited are unlikely to be under strong cultural selection.

1 comment:

Maju said...

Most interesting claim. Pity it's behind a paywall.

A lot of people seems to blindly associate individual behavioural fitness with the success of patrilineages but there is really no evidence supporting that. The trend of Y-DNA to show less diversity than mtDNA actually means only fastest drift, not positive sexual selection.

This paper seems to put the nail in the coffin to such hypothesis, that I could not call anything but "patriarcalist".

Locations of visitors to this page