The reason may be wars between clans structured around male ancestry.
So extreme was that collapse that it was as if there were only one man left to mate for every 17 women.
(Image credit: Courtesy Marcus Feldman) Anthropologists and biologists were perplexed, but Stanford researchers now believe they’ve found a simple – if revealing – explanation.
The collapse, they argue, was the result of generations of war between patrilineal clans, whose membership is determined by male ancestors.
He soon shared his ideas with his high school classmate Alan Aw, also a Stanford undergraduate in mathematical and computational science.
From the point of view of those chromosomes at least, it’s almost as if everyone in a clan has the same father.
That only applies within one clan, however, and there could still be considerable variation between clans. »