Beware of elaborate telescopic meats, they will find their way back to the forest
About 2 million years ago, the human brain rapidly increased its mass until it was double the size of other primate brains.
“This happened because we started to eat better food, like eating more meat,” said researcher Philipp Khaitovich of the Partner Institute for Computational Biology in Shanghai. But the increase in size, Khaitovich continued, “did not make humans as smart as they are today.”
For a long time, we were pretty dumb. Humans did little but make “the same very boring stone tools for almost 2 million years,” he said. Then, only about 150,000 years ago, a different type of spurt happened — our big brains suddenly got smart. We started innovating. We tried different materials, such as bone, and invented many new tools, including needles for beadwork. Responding to, presumably, our first abstract thoughts, we started creating art and maybe even religion.
To understand what caused the cognitive spurt, Khaitovich and colleagues examined chemical brain processes known to have changed in the past 200,000 years. Comparing apes and humans, they found the most robust differences were for processes involved in energy metabolism.
The finding suggests that increased access to calories spurred our cognitive advances, said Khaitovich. (…) Today, humans have relatively small digestive systems and burn 20-25 percent of their calories running their brains. For comparison, other vertebrate brains use as little as 2 percent of the animal’s caloric intake.
