FLICKR, _DJ_Finding food and lighting fires might explain why humans have such big brains, researchers report yesterday (May 23) in Nature.
Humans’ brains are six times as large as those of similarly sized mammals, an observation that has led scientists to ponder for decades what led to such big noodles. Studies suggest social challenges, such as cooperating to hunt, or sharing cultural knowledge spurred the expansion, but a mathematical model to explain human brain evolution finds the environment had a stronger influence.
Study coauthors Mauricio González-Forero and Andy Gardner of the University of St. Andrews developed a computer model to simulate the effects of social, environmental, and cultural challenges on brain size over time. “We were expecting social challenges to be a strong promoter of brain size,” González-Forero tells New Scientist. Surprisingly, environmental challenges won out. About 60 percent of the increase in brain size over ...
