Sorting the chimps from the men:

“A team of molecular biologists have taken a step towards defining what makes us human. It is not so much our differing gene sequences that distinguish us from our primate cousins, but how active those genes are, the team has discovered.

Chimp and human genomes vary by only 1.3 per cent and only a tiny fraction of this actually affects genes. The new research shows how variation in the amount of product of a gene may be as significant to our recent evolution as structural changes.

The greatest changes in gene expression have been in the brain, say the researchers, perhaps explaining why human mental capabilities have evolved so rapidly.” New Scientist