We humans are pretty special: we completely dominate the planet, and we’ve even moved beyond the Earth’s boundaries to explore, and possibly colonize, space.
How have we been able to do so much? In order to find out we must go back to the start, to the evolution of our human species.
Humans first appeared about 2.5 million years ago in East Africa, evolving from a genus of great apes known as Australopithecus. These early humans, such as Homo rudolfensis and Homo erectus, eventually migrated, abandoning East Africa for more promising environments. Adaptation to these new habitats led them to evolve into even more forms of Homo, including Homo neanderthalensis in Europe and Asia.
It wasn’t until 300,000 years ago that modern humans, Homo sapiens, first appeared. This new species of human were not particularly special. Sure, they had large brains, walked upright, used tools and were highly social, but so did the other species of human. For example, Neanderthals hunted large game and used fire long before the emergence of Homo sapiens.
And yet, despite there being nothing particularly special about Homo sapiens, they prospered and overspread the globe; all the other human species died out. Why?
There are two theories to explain this: The Interbreeding Theory suggests that Homo sapiens began mating with the other species of humans – most notably Homo neanderthalensis – and that that resulted in the species’ gradually merging together. There is evidence to back this theory up: the DNA of modern Europeans contains between 1 and 4 percent of Neanderthal DNA, as well as some DNA from other earlier human species.
The Replacement Theory, on the other hand, suggests that Homo sapiens, thanks to their slightly superior skills and technology, pushed other human species toward extinction – either by taking away their food sources or by violently killing them off.
So which of the theories is most likely to be correct? Well, both are likely to be partially correct: Homo sapiens probably drove the other species toward annihilation and simultaneously interbred with them.!