Final answer:
Sub-Saharan Africans likely did not interbreed with Neanderthals, as interbreeding occurred after early humans migrated out of Africa, affecting populations that later became Europeans, Asians, and others.
Step-by-step explanation:
The Neanderthal Genome Project has provided substantial evidence regarding interbreeding between early humans and Neanderthals. The group of humans that probably did not interbreed with Neanderthals are Sub-Saharan Africans. This is because early humans emerged from Africa and subsequently spread out to other parts of the globe. An isolated population of these early humans later interbred with Neanderthals. Thus, interbreeding primarily occurred after early humans had left Africa, affecting populations that would become Europeans, Asians, Australians, and others, but not those who remained in Sub-Saharan Africa.
DNA evidence suggests that populations in Europe, Asia, and Papua New Guinea have some percentage of Neanderthal DNA, indicating that genetic exchange took place between Neanderthals and modern humans as modern humans migrated out of Africa. This exchange happened before the divergence of these groups, which implies that indigenous Sub-Saharan African populations, who did not migrate, likely maintained a genetic makeup distinct from Neanderthals.