There's also the part that no Neanderthal DNA is in black Africans, so it might be that Neanderthal DNA is part of what makes Europeans and Asians a bit distinct from Africans.
Now that, that's interesting. Does it then follow that Neandertal is not of African origin? Or did Neandertal also start off in Africa, but then somehow left and left no trace?
I may have to rent another Holiday Inn Express room and research this.