the investigations of neurobiologist susana herculano at the federal university of rio de janeiro.
Humans have roughly three times as many neurons (86 billion) than our close primate cousins, like gorillas (33 billion) or chimpanzees (28 billion). The Brazilian scientists found that the number of neurons is directly linked to brain size, as well as to the amount of energy needed to feed the brain. Thus, humans need brains consume 20% of our body’s energy when resting, compared with 9% in other primates – a hefty cost. This begged the question, however: from where did our ancestors get all this extra energy to grow such a large brain in a relatively short evolutionary time frame?cooked food!
yes, but what did they eat?
the answer is here.