“It makes it hard to argue that there was ever some … special evolutionary event or genetic event that triggered the evolution of humans as we know them,” he added. Humans have been continuously evolving through the mixing of varied populations for hundreds of thousands of years. (In fact, Scally posits that our species did not originally evolve from a single population in Africa, but rather from many interconnected populations spread out across the continent.) We consider it very human to mix with other races at this point in time. Interestingly enough mixing with other species was commonplace.