From Science Daily:
Understanding how and why we evolved such large brains is one of the most puzzling issues in the study of human evolution. It is widely accepted that brain size increase is partly linked to changes in diet over the last 3 million years, and increases in meat consumption and the development of cooking have received particular attention from the scientific community. In a new study published in The Quarterly Review of Biology, Dr. Karen Hardy and her team bring together archaeological, anthropological, genetic, physiological and anatomical data to argue that carbohydrate consumption, particularly in the form of starch, was critical for the accelerated expansion of the human brain over the last million years, and coevolved both with copy number variation of the salivary amylase genes and controlled fire use for cooking.
With global increase in obesity and diet-related metabolic diseases, interest has intensified in ancestral or ‘Palaeolithic’ diets, not least because — to a first order of approximation — human physiology should be optimized for the nutritional profiles we have experienced during our evolution. Up until now, there has been a heavy focus on the role of animal protein and cooking in the development of the human brain over the last 2 million years, and the importance of carbohydrate, particular in form of starch-rich plant foods, has been largely overlooked.
Hardy’s team highlights the following observations to build a case for dietary carbohydrate being essential for the evolution of modern big-brained humans:
(1) The human brain uses up to 25%…