Sharp drops in global temperatures helped seal the fate of three extinct hominin species, including our close relatives, the Neanderthals, according to thousands of archaeological specimens and a model of past climate conditions.
The branch on the tree of life that is the genus Homo is a gnarled, twisty one with many offshoots and dead ends. Of at least six species who have walked the Earth within the past few million years, all but one have gone extinct, for reasons that are largely a mystery.
Learning Sustainability 