As big game declined, we are told, humans had to get smarter to catch smaller prey:
The researchers posit that by killing off large animals, an abundant source of much-needed fat, Homo erectus, an ancient human species, was forced to move to chase smaller creatures — and the smaller they were, the more ingenuity it took to catch enough of them to meet dietary needs. This, in turn, selected for bigger and more capable brains in the species.
In a paper published on the peer-reviewed MDPI website, Miki Ben-Dor and Prof. Ran Barkai of Tel Aviv University presented their “unifying” hypothesis that the decline in prey size was the “one driver for many key physiological and cultural phenomena in human prehistory.”
Stuart Winer, “Israeli researchers offer new theory on human brain evolution: We were hungry” at Times of Israel
The paper is open access.
Hmmm. If the ability to hunt small prey requires a lot more intelligence, cats are definitely smarter than people, let alone smarter than dogs (a more frequently heard claim).
Note: In reality, the cat is very well adapted to living off small rodents. Natural endowments enable him to get by without a human level of intelligence. Of course, large numbers of cats prefer to live with humans and retain the begging skills they learned as kittens. It pays better than stalking mice full time.
A small selection of some more of the many theories about the human brain: Eating fat, not meat, led to bigger human type brains, say researchers. Theories of the evolution of the human brain are a war of trivial explanations that no one dare admit are too trivial for what they purport to explain. It’s like blaming World War II on indigestion, only monstrously bigger.
Earlier discussion of the fat theory.
Starchy food may have aided human brain development
Do big brains matter to human intelligence?
Human evolution: The war of trivial explanations
and
What great physicists have said about immateriality and consciousness