DID shrinking guts and high-energy food help us evolve enormous, powerful brains? The latest round in the row over what鈥檚 known as the 鈥渆xpensive tissue hypothesis鈥� says no. But don鈥檛 expect that to settle the debate.
The hypothesis has it that in order to grow large brains relative to body size, our ancestors had to free up energy from elsewhere 鈥� perhaps by switching to rich foods like nuts and meat, which provide more calories and require less energy to break down, or possibly by learning to cook: cooked food also requires less energy to digest.
and of Duke University in Durham, North Carolina, turned to New World monkeys to explore the hypothesis. Previous studies offer a wealth of data on the monkeys鈥� diets and show that their brain size varies greatly from species to species. But when the pair controlled for similarities between related species, they found no correlation between large brains and small guts (Proceedings of the Royal Society B, ).
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As at the University of Oxford points out: 鈥淚t is one thing to say that the hypothesis doesn鈥檛 apply to New World monkeys, and another to extrapolate that to humans.鈥�
