Contentious Hypothesis Posits Humans Brains Grew Larger as We Hunted Smaller Prey STEPHANIE PAPPAS, LIVE SCIENCE 12 MARCH 2021 Over the course of the Pleistocene epoch, between 2.6 million years ago and 11,700 years ago, the brains of humans and their relatives grew. Now, scientists from Tel Aviv University have a new hypothesis as to why: As the largest animals on the landscape disappeared, the scientists propose, human brains had to grow to enable the hunting of smaller, swifter prey.
This hypothesis argues that early humans specialized in taking down the largest animals, such as elephants, which would have provided ample fatty meals. When these animals' numbers declined, humans with bigger brains, who presumably had more brainpower, were better at adapting and capturing smaller prey, which led to better survival for the brainiacs.