From the Harvard Gazette, November 18:
Metabolic rates outpaced ‘couch potato’ primates thanks to sweat, says new study
Humans, it turns out, possess much higher metabolic rates than other mammals, including our close relatives, apes and chimpanzees, finds a new Harvard study. Having both high resting and active metabolism, researchers say, enabled our hunter-gatherer ancestors to get all the food they needed while also growing bigger brains, living longer, and increasing their rates of reproduction.
“Humans are off-the-charts different from any creature that we know of so far in terms of how we use energy,” said study co-author and paleoanthropologist Daniel Lieberman, the Edwin M. Lerner Professor of Biological Sciences in the Department of Human Evolutionary Biology.
The paper, published Monday in Proceedings of the National Academy of Sciences, challenges a previous consensus that human and non-human primates’ metabolic rates are either the same or lower than would be expected for their body size....*****...Using a new comparison method that they say better corrects for body size, environmental temperature, and body fat, the researchers found that humans, unlike most mammals including other primates, have evolved to escape a tradeoff between resting and active metabolic rates.Animals take in calories through food and, like a bank account, spend them on expenses mostly divided between two broad metabolic categories: resting and physical activity. In other primates, there is a distinct tradeoff between resting and active metabolic rates, which helps explain why chimpanzees, with their large brains, costly reproductive strategies, and lifespans, and thus high resting metabolisms, are “couch potatoes” who spend much of their day eating, said Lieberman....
.....MUCH MORE