JOIN US Humans may have evolved big brains partly due to a DNA "typo" in their genetic code, according to a new study which found that the mutation was also present in our evolutionary "cousins" - the Neanderthals and Denisovans.
The mutation, however, is not found in humans' closest living relatives, the chimpanzees. As early humans evolved, they developed larger and more complex brains, capable of storing and processing a lot of information.
Scientists previously identified a human gene which they believe was behind the expansion of a key brain region known as the neocortex.
The gene likely arose about five or six million years ago, after the human line split off from chimpanzees.
Researchers at Max Planck Institute of Molecular Cell Biology and Genetics in Germany have now found a tiny DNA mutation that appears to have changed the function of the gene, sparking the process of expansion of the neocortex.
It may have led to the brain's expansion by dramatically boosting the number of brain cells found in this region, 'BBC News' reported.
"A point mutation in a human-specific gene gave it a function that allows expansion of the relevant stem cells that make a brain big," said Dr Wieland Huttner from Max Planck Institute.
"This one, as it is fixed in the human genome - so all living humans have the gene - apparently gave a tremendous selection advantage, and that is why we believe it spread in the human population," said Huttner. The research was published in the journal Science Advances.