Humans evolved large brains thanks to an increased metabolic rate, suggests new research. Authors of a new study say that humans evolved a higher body fat percentage than other primates in order to provide the energy required to fuel this increased metabolism.

The team took direct measurements of the daily energy expenditure from 141 people and compared the measurements to data from all known species of great ape. Their results showed that humans have evolved a faster metabolism and a higher daily energy budget than chimpanzees and bonobos, gorillas, and orangutans – by about 400, 635, and 820 kcal per day, respectively. Results of the analysis confirmed the researchers’ hypothesis that the increased metabolic rate of humans helps accommodate larger brains, which consume more calories. The higher metabolism also supports having more offspring and a longer lifespan.

Authors:

Herman Pontzer, Mary H. Brown, David A. Raichlen, Holly Dunsworth, Brian Hare, Kara Walker, Amy Luke, Lara R. Dugas, Ramon Durazo-Arvizu, Dale Schoeller, Jacob Plange-Rhule, Pascal Bovet, Terrence E. Forrester, Estelle V. Lambert, Melissa Emery Thompson, Robert W. Shumaker & Stephen R. Ross.

Corresponding author:

Herman Pontzer

Original paper, published on May 4, 2016 in Nature.