Narrator: This is Science Today. A new study suggests meat-eating was essential for human evolution. Katherine Milton, a professor of biological anthropology at the University of California, Berkeley, says by routinely adding meat to their plant-based diets, proto humans roaming the African savanna about 2 million years ago were bolstered by high quality nutrition.
Milton: So I sort of see meat as satisfying many nutritional demands and then letting early humans use their plant foods primarily as an energy source.
Narrator: This would be an ideal diet for fueling brain development and may have led to selective advantages.
Milton: Perhaps they were healthier, they had higher reproductive output than all the other members of their species who were not getting this little increment of meat every day. And little by little, this behavior of eating meat began to spread through the population until finally, it became a habitual behavior of that particular organism and translated ultimately, into being human.
Narrator: For Science Today, I'm Larissa Branin.