Genes may reveal differences between humans and chimps

IRISH scientists have identified human specific genes that could unlock the mystery of what makes us different from the chimpanzee, our closest relative.

Six million years ago, chimpanzees and humans diverged from a common ancestor and evolved into unique species.

Humans and chimpanzees are 99% identical, but small genetic differences play a major role in determining what it is to be human.

Scientists at Trinity College Dublin identified specific genes that originated during the evolution of humans following the separation from chimpanzees.

Up to now, prevailing wisdom was that new genes could only evolve from duplicated or rearranged versions of pre-existing genes.

It seemed unlikely that evolutionary processes could produce a functional, protein-coding gene from what was once inactive DNA.

There was evidence that phenomenon occurred in flies, yeasts and primates, but no such genes had been found to be unique to humans – until now.

The Irish scientists, whose work was published in Genome Research yesterday, conducted a evolutionary analysis of the human genome sequence in comparison with those of chimpanzees and gorillas.

Dr David Gonzalez Knowles and Dr Aoife McLysaght identified three human genes that have no counterpart in any other organism.

“They are unlike any other human genes and have the potential to have a profound impact,” said Dr McLysaght.

Even though the genes had not yet been characterised, it was “tempting” to speculate that human-specific genes were important for human-specific traits, she said.