Wealth and power may have played a stronger role than "survival of the fittest," which led to dramatic decline in genetic diversity in male lineages four to eight thousand years ago, reveals a new study.
In a study led by scientists from Arizona State University, the University of Cambridge, University of Tartu and Estonian Biocentre, researchers discovered a dramatic decline in genetic diversity in male lineages four to eight thousand years ago, likely the result of the accumulation of material wealth, while in contrast, female genetic diversity was on the rise. This male-specific decline occurred during the mid- to late-Neolithic period.
Melissa Wilson Sayres, a leading author and assistant professor with ASU's School of Life Sciences, said that instead of "survival of the fittest" in biological sense, the accumulation of wealth and power might have increased the reproductive success of a limited number of "socially fit" males and their sons.
It was widely recognized among scientists that a major bottleneck, or decrease in genetic diversity, occurred approximately 50 thousand years ago when a subset of humans left Africa and migrated across the rest of the world.
Signatures of this bottleneck appeared in most genes of non-African populations, whether they are inherited from both parents or, as confirmed in this study, only along the father's or mother's genetic lines.
The researchers believed that this would be relevant for informing patterns of genetic diversity across whole human populations, as well as informing their susceptibility to diseases.
The study is published in the journal Genome Research.