Humans have more brain neurons than any other primate—but these extra neurons come at a price. Our brains consume 20% of our body’s energy when resting, compared with 9% in other primates. Scientists have suggested that cooking may have helped humans get that extra energy while spending less time foraging—because cooking effectively predigests food, making it easier for our guts to absorb calories.
Now, a new study supports this idea, finding that raw food alone wouldn’t have allowed our ancestors’ brains to grow: They would have had to spend more than 9 hours a day eating to get enough energy.
On Nov. 8, Ann Gibbons of ScienceNOW hosted a live chat on diet and evolution with primatologist Richard Wrangham and neuroscientist Suzana Herculano-Houzel. The full text of the discussion is below.
This story provided by ScienceNOW, the daily online news service of the journal Science.