Extinction of Large Animals Raised the Human Brain
A new hypothesis that the enlargement of the human brain was due to the extinction of large animals is drawing attention. The chimpanzee’s brain has remained the same for 7 million years, but humans’ brain capacity has increased by about three times since the first appearance, from 650 cc to 1500 cc. There are several hypotheses that explain why the human brain has grown so large.
Among them, the sociality hypothesis and the ecological intelligence hypothesis are receiving the most support. The social hypothesis is the theory that the brain grows in the process of humans communicating with each other as a group, and the ecological intelligence hypothesis is the theory that the brain capacity has increased as a result of using a lot of head to survive by adapting to the environment.
Ancient humans hunting large animals, elephants. A new hypothesis has been raised that the enlargement of the human brain was due to the extinction of such large animals.
However, neither hypothesis came to a definite conclusion in that humans are not the only animals that live in groups, and that other animals have worked tirelessly to survive in harsh environments.
However, Dr. Miki Ben-Dor and Professor Ran Barkai of the Department of Archeology at Tel Aviv University in Israel have a new hypothesis about changes in brain capacity from the first appearance of mankind to the agricultural revolution (around 10,000 BC). Came up.
According to him, when humans first appeared in Africa 2.6 million years ago, the average weight of land mammals reached 500 kg. However, just before the start of the agricultural revolution, the size of land mammals decreased by more than 90%, reducing the average weight to tens of kilograms.
Humans cause the extinction of large animals
The decisive reason for this reduction in the size of animals is that it is because of humans. In other words, it explains that humans evolved into top predators specialized in hunting large animals, causing their ultimate extinction. Evidence that humans have been a major factor in the extinction of large animals has been accumulating quite a bit in recent years.
As the large animals disappear, they claim that the brain capacity has increased as humans adapt to hunting fast-moving small animals and require higher cognitive abilities. The results of this study were published in the latest issue of “Quaternary,” published by MDPI, a world-renowned academic paper publisher.
According to him, there were six species of elephants in Africa in the past, and they accounted for more than half of all herbivores biomass that humans hunted. In other words, these large animals provided humans with fat, an essential source of energy.
Early evidence from East Africa shows that Homo sapiens only appeared in certain regions after a significant decline in the number of elephant species. The researchers compared the size of animals found in archaeological cultures in East Africa, Southern Europe, and Israel, and found that human brain volume increased after a significant decrease in the population of large animals weighing over 200 kg.
As the prey became smaller, it was forced to hunt small and fast animals, and humans had to become more cunning and daring. They claim that this has resulted in a larger human brain and that language has developed as information exchange about places where prey can be found is required.
As the animals keep getting smaller, they start the agricultural revolution.
In other words, having to hunt dozens of gazelles instead of one elephant created long-term evolutionary pressure on human brain function. Hunting small animals that move very fast requires not only more sophisticated hunting tools, but also physical conditions suitable for tracking.
In addition, since rapid decision-making based on empirical knowledge about animal behavior is necessary for rapid tracking, cognitive activity is bound to increase. The researchers explained that such diversified and increased information should be stored in a larger memory.
In order to hunt smaller and faster animals, humans had to develop new weapons.
Dr. Miki Ben-Dor said, “As animals continue to shrink in size, humans have invented bows and arrows and domesticated dogs to continue hunting.” However, by the end of the Stone Age, animals became smaller and humans, who had no choice but to devote more energy to hunting, eventually started the agricultural revolution.
The researchers argued that when the agricultural revolution no longer focused on hunting, the human brain capacity was reduced to the current 1,300-1,400 cc. This is because in the presence of domesticated animals and plants, there is no longer a need to allocate cognitive abilities to the task of hunting.
Professor Ran Bakai said, “Wherever humans, whether Homo erectus or Homo sapiens, were mass extinct, large animals were extinct. But other human species, such as our cousin Neanderthal, were extinct as their large prey disappeared, whereas Homo. Sapiens was able to survive the agricultural revolution.”
Extinction of Large Animals Raised the Human Brain - /10