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.