Humans Got Punier As Energy-Hungry Brains Became Stronger, New Study Suggests

The human brain accounts for just 2.5 percent of body mass but it consumes a whopping one-fifth of our energy. The question of how and why we evolved such big, energy-hungry brains has long plagued scientists, but a new study offers a relatively simple explanation. Researchers in China say that starting roughly 6 million years ago, evolution supported intellect over brawn, and our bodies compensated by diverting energy from muscle production to brain development. In other words, humans became pu...