Final answer:
Neanderthal alleles show closer genetic relationships to human alleles from Europe and Asia than those from Africa, due to interbreeding that occurred as modern humans migrated out of Africa.
Step-by-step explanation:
Some Neanderthal alleles are more closely related to human alleles from Europe and Asia than to those from Africa. This conclusion is drawn from genomic studies, indicating a genetic overlap between Neanderthals and non-African modern humans.
Further explanation of these findings reveals that due to interbreeding between early modern humans and Neanderthals, people living outside of Africa today carry about 1 to 4 percent of Neanderthal DNA. This interbreeding likely occurred as modern humans migrated out of Africa and encountered Neanderthals inhabiting Europe and Asia. As a result, Europeans and Asians share a closer genetic connection to Neanderthals compared to Africans, who predominantly retain the genetic heritage from the ancestral African population from which modern humans originated.
Nonetheless, the understanding of human evolution is multifaceted, and although Neanderthals and modern humans interbred, this does not negate the fact that the majority of the human genome is indeed rooted in Africa, given the great genetic diversity found on the continent.