A study suggests that human beings evolved toward the development of larger brains instead of muscles.
… Read the rest
To gain insights into how the human brain evolved, scientists compared the metabolisms of humans and animals such as chimpanzees, mice and rhesus monkeys. They focused on how much energy each species devoted to the brain and body.
The researchers analyzed more than 10,000 compounds known as metabolites, which are small molecules formed by, or necessary to, metabolism, such as sugars and fats; the building blocks of proteins, DNA and cell membranes; and chemical signals given off by cells. They investigated metabolite levels in the kidney, thigh muscle and three brain regions — the primary visual cortex, which is involved in vision; the cerebellar cortex, which helps coordinate muscular activity; and the prefrontal cortex, which plays a major role in complex mental behavior, decision making and social behavior.
The investigators next compared how much the metabolisms of these animals differed with how far apart these species are evolutionarily.