Comment: More_than_two_humans_who_came_out_the_trees,_probably_many_more_responding_to_an_environmental_effect._Africa_is_found_to_have_much_more_genetic_diversity_than_the_rest_of_humanity,_even_with_those_who_left_Africa_having_mated_with_Neanderthals,_thus_preserving_part_of_their_inferior_DNA.