Abstract

Homo sapiens is possibly the most ecologically plastic animal species ever, capable to overcome climatic variability beyond its physiological limits by means of culture. This adaptability has a strong cultural component which required the development both new technologies and major social changes sometimes in our distant past1,2. Highly contentious archaeological evidence suggests these innovations may have predated the emergence of our own species3. Here we studied climate niche width evolution in Homo, using fine-detailed palaeoclimatic data while controlling for phylogenetic effects. Our results point to sudden widening of the climatic niches exploited by Homo starting with the emergence of H. heidelbergensis. From the Middle Pleistocene, Homo ceased to be confined to physiologically suitable regions, despite progressive harshening of global climatic conditions. These results suggest cultural modernity, and its associated technological advancements, including habitual use of fire and clothing, appeared before the emergence of our own species.