Do big brains stem from cooler climates?
Big brains need cool climates to evolve and do their job well, according to new research published in the journal Climatic Change.
If you've been wondering who to thank for your extraordinarily large brain thank the Earth's last 50 million years of chilly weather, says David Schwartzman, a biology professor at Howard University and chief author of the report.
Without it, our savannah-savvy, tool-wielding ancestors Homo habilis and Homo erectus might not have emerged, the study claims. Why? Because big brains generate a lot of heat, and we get rid of heat much more easily when the climate's cool.
It's not hard to see where this is going. Burning fossil fuels and warming up the planet will make it harder for our struggling brains to cool down, says Dr Axel Kleidon at the University of Maryland.
'An important implication', Dr Kleidon concludes, 'is that global warming is likely to lead to environmental conditions less suitable for human metabolic activity in their natural environment ... due to a lower ability to loose heat.'
(Confused? The Kinks' song, 'Apeman', sums up Kleidon's concerns admirably.)