Scientists at Tel Aviv University have named an unexpected reason for the appearance of a large human brain, which is the extinction of megafauna, that is, for example, large animal species. This forced humans to switch to smaller animals, which contributed to the development of cognitive abilities. This is reported in an article published in the journal Quaternary. A brief summary of the scientific work is described in a press release on Phys.org.
Experts have compared the size of animals whose remains have been found in various archaeological cultures in East Africa, Southern Europe and Israel. It turned out that in all cases there was a significant decrease in the prevalence of animals weighing more than 200 kilograms, combined with an increase in the brain volume of human ancestors.
Approximately 2.6 million years ago, when the first humans appeared, the average mass of mammals reached about 500 kilograms. Just before the advent of agriculture, that number dropped by more than 90 percent. Reducing the size of game and hunting small and nimble animals demanded new skills from people, which, in turn, led to the development of speech and language. Communication between people facilitated hunting and made it possible to transmit information about the location of prey. According to the hypothesis of the researchers, all means should serve one purpose: to preserve the energy of the body.
In the past, there were six different species of elephants in Africa, accounting for more than half the biomass of all herbivores hunted by humans. They provided people with a lot of fat and allowed them to get much more energy than was spent on hunting. However, people began to spend more energy on hunting small animals than they could compensate for, so it became more profitable to breed domesticated animals, which then led to a decrease in brain volume.