If you were thinking that it is the brain and its functions that separate human beings from all other life on Earth then the new study has something exciting to reveal. Human muscles also are quite special in the way they function.

Researchers in China have studied the evolution of metabolites, which are small molecules like sugars, vitamins and amino acids. They play an important role in human being's psychological functions. As the evolution took place, metabolite concentrations also evolved quite rapidly in two types of tissues, in the brain and muscles.

Researchers from Chinese Academy of Science-Max Planck Gesellschaft Partner Institute for Computational Biology wanted to know the factors outside genome affecting human evolution. For the same, they observed the human metabolome, a collection of metabolites present in human tissues.

Lead researcher Philipp Khaitovich finds metabolites to be more dynamic than genome. As per Khaitovich, metabolites can reveal more about what makes us human. "It is also commonly known that the human brain consumes way more energy than the brains of other species; we were curious to see which metabolic processes this involves", affirmed Khaitovich.

After studying the metabolome, it was discovered that the human brain has evolved four times faster than that of the chimpanzee. But more surprising was that the human muscles have shown even higher amount of metabolic change and 10 times faster than that of the chimpanzees.