We are Borg
Once upon a time it was supposed that Homo sapiens went around the globe wiping out other species, whether through deliberate acts of genocide, or by accident, simply by being better at hunting and gathering and dominating the food supply until the other human species dwindled away.
However recent genetic evidence suggests otherwise. Recent genetic evidence suggests that most humans on the planet have 1-4% neanderthal DNA, and some have 1-6% denisovan DNA (the denisovan hominid, of which nothing is known besides the fact that they lived in a cave named Densiova and that they mated with Homo sapiens people. Nothing else is known about them. Nothing.)The evidence regarding neanderthal DNA also suggests that the interbreeding occurred pretty much the exact minute that Homo sapiens set foot out of Africa. And while some Africans may pride themselves on having 100% Homo sapiens DNA, there are those who theorise that before Homo sapiens even left Africa they’d already interbred with other African species of human.
It seems that we didn’t wipe out other species, we assimilated them. The neanderthals didn’t die out, they became part of us. Our ancestors left Africa and thought “look at those strange people with orange hair and beige skin… orange hair and beige skin would look ever so nice with our cute vertical foreheads and pointy chins. Let’s assimilate them.” – well not quite like that but you get the idea. Homo sapiens are not the Daleks of the human species, we are Borg. You will be assimilated. Resistance is Fertile Futile.