Past Extinctions of Homo Species Coincided with Increased Vulnerability to Climatic Change

The message of the extinction rebellion protest movement, that human-induced climate change poses a threat to our species' survival, is reawakening consciences worldwide. Climate change is known to have been a major player in the turnover of species throughout the geological record. Were our ancestors, forged through the continually oscillating Pleistocene glacial cycles, not shielded from this danger? To date, the lack of sufficiently detailed and long-timescale climate information and the scarcity of data on early humans have left this question unanswered. By combining a mammoth data collation and analysis with novel paleoclimate modeling, we discovered that, for vanished human species, extinction had a candid, unquestionable climatic drive, which in the case of Neanderthals adds to the effect of competition with ourselves. Notably, Homo sapiens is the only species whose climatic niche was still expanding toward the end of our analysis, when the Neanderthals went extinct.