On 2016 Jul 05, Herman Pontzer commented:
Thank you for the comment. We haven't forgotten about the importance of cooking: we include it among the critical human adaptations that make more energy available (reference 25, Carmody et al. 2011). In the penultimate paragraph of the main text, we write:
"...the adoption of cooking<sup>25</sup> ... effectively increase[s] the net energy gained from foraging, and may have had an essential role in the evolutionary expansion of the hominin energy budget."
However, as we discuss in the paper, increased food energy intake is necessary but not sufficient in accounting for the suite of metabolically costly human traits. To take advantage of the extra calories from cooking (or from other dietary changes that increase the mean calories/gram of food) requires evolved physiological changes to increase the metabolic rate. Previously, the prevailing view of metabolic evolution in humans (and other mammals) assumed that metabolic rates were similar across the hominoids, with no difference in calories/day (accounting for size) across humans and other apes. Our paper shows that humans have undergone an evolutionary increase in metabolic rate that accounts for the (estimated) extra caloric expenditure on brains, reproduction, etc. It will be interesting, in future analyses, to begin parsing the contributions from cooking, dietary changes, and other adaptations to the evolution of human metabolic rate.
This comment, imported by Hypothesis from PubMed Commons, is licensed under CC BY.