Speaking gene takes birth for 2 n 1/2 million years

Gene which sparked human brain leap identified

       By duplicating itself two and a half million years ago the gene could have given early human brains the power of speech and invention, leaving cousins such as chimpanzees behind.

The gene, known as SRGAP2, helps control the development of the neocortex – the part of the brain responsible for higher functions like language and conscious thought.

Having an extra copies slowed down the development of the brain, allowing it to forge more connections between nerve cells and in doing so grow bigger and more complex, researchers said.

In a study published in the Cell journal, the scientists reported that the gene duplicated about 3.5 million years ago to create a "daughter" gene, and again a million years later creating a "granddaughter" copy.

Although humans and chimpanzees separated six million years ago, we still share 96 per cent of our genome and the gene is one of only about 30 which have copied themselves since that time.
The first duplication was relatively inactive but the second occurred at about the time when primitive Homo separated from its brother Australopithecus species and began developing more sophisticated tools and behaviours.