Humans' 'big brain' may have been caused by a DNA glitch, study suggests.
Humans have coursed through multiple evolution and mutation to arrive at the point of what we look like today, including the size of our brain. Early humans developed bigger and more complex brains, which allowed them to process and store more information.
Neanderthals, human 'cousin' / Flickr
Our cousins, the Neanderthals and Denisovans went through mutation themselves.
Scientists have already located the gene responsible for the expansion of the neocortex, the key region of the brain which is regarded as the most recently evolved.
They found out that the gene involve emerged five or six million years ago just around the time after the human line had split off from the chimpanzees.
Just recently, researchers discovered a point mutation that seemed to have changed the function of the gene igniting the process of expansion in the neocortex. The brain cells in this part of the brain have increased dramatically.
"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 of the Max Planck Institute of Molecular Cell Biology and Genetics in Dresden, Germany who led the research.
All living humans is believed to have this gene and may hold a certain selection advantage.
It was between two to six million years ago that the human brain grew bigger around the time that humans also started to walk upright and use tools.
By 800,000 years ago, the brain continued to increase its size. This was partly one of the reasons human beings survived in a changing world.
This gene may just be one of the many genetic changes that gave us humans our unique intelligence and rationality.
The study is published in Science