>mainline of the genetic stream This is a tricky concept. Could it be said over 50,000 years ago that Homo Sapiens' ancestors were the mainline? I wouldn't ret

>mainline of the genetic stream This is a tricky concept. Could it be said over 50,000 years ago that Homo Sapiens' ancestors were the mainline? I wouldn't retroactively call it that because it presumes that it was clear at the time that it would be the definitive dominant subspecies. I think a better phrasing would be "genetic divergences, some of which were preserved by the cross-merging with the only surviving genetic stream", or something of the sort.