A spurt in human intelligence about 150,000 years ago was caused by eating (mostly) cooked meals, which would have lessened the energy needs of our digestion systems, thereby freeing up calories for our brains, says researcher Philipp Khaitovich of the Partner Institute for Computational Biology in Shanghai.

But some of our most common mental health problems, ranging from depression and bipolar disorder to autism and schizophrenia, may be by-products of the metabolic changes that happened in an evolutionary “blink of an eye,” Khaitovich said.