Chimpanzee and human genes studied

LOS ANGELES, Nov. 14 (UPI) -- U.S. researchers say they have identified a new way to pinpoint the genes that separate humans from chimpanzees, the human's closest living relative.

The UCLA scientists say 6 million years ago, chimpanzees and humans diverged from a common ancestor and evolved into unique species but humans still share more than 95 percent of their genetic blueprint with chimps.

"During evolution, changes in some genes altered how the human brain functions," said Daniel Geschwind, principal investigator and professor of human genetics at the David Geffen School of Medicine. "Our research has identified an entirely new way to identify those genes in the small portion of our DNA that differs from the chimpanzee's."

By evaluating the correlated activity of thousands of genes, the UCLA team identified not just individual genes, but entire networks of interconnected genes whose expression patterns within the brains of humans varied from those in the chimpanzee.

"Genes don't operate in isolation -- each functions within a system of related genes," said first author Michael Oldham, UCLA genetics researcher

The research is detailed in the Nov. 13 online edition of The Proceedings of the National Academy of Sciences.