When compared to other species, humans have enormous brains. Researchers say our brains managed to develop better than apes’ brains was thanks to humans’ metabolism.
Metabolism refers to the many processes through which our body burns calories. It was determined that human metabolism acts way faster than closely-related primates’ metabolism. This is also supported by the increased amount of body fat present in our bodies. Which provides the necessary energy to fuel our advanced metabolism.
Faster, smarter, fatter
A better metabolism diverts into a better development of the brain. The finding was confirmed through the analysis of 141 humans and 56 apes. Researchers included gorillas, orangutans, chimpanzees and pygmy chimpanzees. Taking into account body size, the energy output of the participants was measured over the course of 10 days, as the humans took part in their day-to-day activities. The results showed how humans ended up burning an average of 600 more calories than the apes.
The leading author of the study, Herman Pontzer commented that “every gram of brain uses an enormous amount of calories.” Our brain stands at a volume of 1200ml, thus being twice as large than the largest brain of an ape.
New research out from our colleagues in biological anthropology: https://t.co/mQzFhl7mNA
— CambridgeArchaeology (@UCamArchaeology) April 29, 2016
According to the research, there are several factors that helped into developing the human brain as it stands in the present. Humans learned to hunt and share food, which allowed the species to gain access to high-calorie sustenance. This significant storage of fat was also developed in order to cope with periods of starvation whenever there was no food available.
The study was carried out over the last two decades. It stems from the hypotheses of the reasons behind the dramatic expansion of the human brain between the evolutionary stages of Homo erectus and Homo sapiens. Some scientists hypothesized that humans sacrificed muscle mass to store energy, as they learned to walk and run more efficiently. Nevertheless, it seems the answer comes from a different mechanism.
Although the results of the study seem promising, there is still much to discover since the research was performed only on adults. In children, the brain takes up to two-thirds of the whole metabolism processes, while the adult needs only about one fourth. This was pointed out by Christopher Kuzawa from Northwestern University. He also added that as the child grows, the body sets its energy output towards developing the brain while the body growth rate is slowed; eventually, the flux of energy is inverted and the brain energy costs decrease as the body growth rate increases.
An adult male gorilla Gorillas are the largest ape, but they expend less energy for their size than humans https://t.co/nkQ5zhYryM
— rasi (@twisira) May 4, 2016