I have put some work into untangling the attributions: will everyone please pay more attention to the "quote boxes" that begin and end text.
ldwechsler wrote:Note that Thandi, a particularly variated individual, had no problems coupling with Victor.
Weird Harold wrote:Coupling isn't the problem, procreation is. Also, Mfecanes are not yet a separate species, they're just close; as in a couple of generations away.
tlb wrote:I have just been made aware of blood type incompatibility, which is one possible cause of sterility. So something like that could easily stop procreation, without affecting coupling.
ldwechsler wrote:Major changes usually take more than a couple of generations. Go back far enough and we're all pretty much related. I read somewhere that everyone with roots in Western Europe is likely descended from Charlemagne.
But a couple of generations in and you have a fairly small sample. It takes time to spread.
saber964 wrote:According to geneticist 1 in 8 people in China and central Asia are related to Genghis Khan
ldwechsler wrote:Keep in mind that related to is not the same as descended from...the common ancestor might be generations earlier.
The point is that it takes quite a few generations to really get a major genetic change to be common, at least for humans.
And not being able to breed requires real change. Lions and tigers breed and I think tigons can actually continued to breed...are not sterile. There are major genetic problems, however, but they are sometimes overcome.
I doubt the differences between those from Ndebele and other planets would be that great.
The source of the quote about blood type incompatibility used the specific example of a Chinese person with a European spouse; they could possibly have one child, but might be incapable of another because the mother's body rejects the fetal blood type difference.
Also, I expect that geneticists were talking about "descended from", not just "related to", since neither individual procreated sparingly. It's good to be the King, was closer to their motto.