Lucy, Darwin, and Black Friday!
3.2 Million years ago, Lucy died. Her remains were found on this day in 1974. Before Lucy, it was widely believed that hominins evolved big brains first, and then became bipedal later. Lucy, however, was clearly built for bipedal walking — an extremely rare adaptation for mammals — and yet her skull only had space for a brain about the size of a chimpanzee's. Her cranial capacity was less than 500 cubic centimeters, or roughly one-third as big as that of a modern human.
What finding Lucy proved to the world was that there were more than one early human species living at the same time with the ever-so-crazy Neanderthals party tribes -- I have my sources -- and in a close geographical proximity too. Combined this finding with the more recent finding in 2011 of even another species, the Australopithecus Deyiremeda, and there can be no doubt that this area of the world was a lab of human test done by none other than... well, as Giorgio A. Tsoukalos would say: Ancient Aliens!