@ergo @nprofile1q... @Caleb James DeLisle @Tio @TROM you should look into something called ring species, there's a bunch of examples of salamanders that can breed with neighboring salamanders but can't breed with the salamanders that are 2 sections over. there's also plenty of examples of fertile hybrids like coywolves.
essentially, the idea of species is a social construct with almost no bearing for the ambiguity and messiness of genetic reality. it's great for explaining to children that horses are different from cats but anyone who's interested in this stuff should ignore it. the fact that there are multiple extinct hominids that interbred with humans also disproves the "one species the human species" nonsense.
if you want to apply the genetic distance standards to humans that we apply to animals, humans should AT MINIMUM be broken up into 3 distinct subspecies going by the fst distance between africans and australian aboriginals.