We are used to seeing our evolution as being like a tree with many extinct branches of other hominid ┬áspecies, that lead to the one surviving species of us, Homo Sapiens. But with DNA testing of other ancient humans, such as Neanderthals and more recently Denisovans, the picture emerges of more an intertwining braid of species and our “tree” starts to look more like a “delta”.

This article is an opinion piece in Aeon by John Hawks, anthropology professor at the University of Wisconsin-Madison:
Human evolution is more a muddy delta than a branching tree