From TFA: > Because Homo sapiens went through a series of near extinction level events before eventually triumphing – periodically reduced to a few thousand su

From TFA: > Because Homo sapiens went through a series of near extinction level events before eventually triumphing – periodically reduced to a few thousand surviving members clinging on in a handful of African enclaves – we have very little genetic variation. The human family tree spreads out from a few individuals to encompass all of us.