[aruanan]

The findings are consistent with the notion that populations in close geographic proximity that speak linguistically similar languages are more likely to exchange genes.

Or that people are less likely to exchange genes with people who don't live in their proximity (think of the equipment of the barnacle) and who aren't of their ethnic/linguistic group.

[SunkenCiv]

Smaller family sizes and/or “open marriages” (infidelity, high rate of remarriage after accidental death, promiscuity etc etc) will always result in greater so-called diversity when compared with descendants of early riverine agricultural boom populations, when family sizes and infant mortality fell. :’)