A lot of people assume that Neanderthals were either a subspecies of humans or were just a separate race; but that depends on which view you wish to adopt. read more
If Haldaneās Law applied to the progeny of Neanderthals and humans, then female hybrids would survive, but male hybrids would be absent, rare, or sterile. Interbreeding between male Neanderthals and female humans, as the only possible scenario, accounts for the presence of Neanderthal nuclear DNA, the scarcity of Neanderthal Y-linked genes, and the lack of mitochondrial DNA in modern human populations. read more