That's the conclusion of researchers who have shown that 99.4 per cent of the most crucial bits of DNA in chimp and human genes are identical.

The homo genus only includes modern man, Homo sapiens, and our immediate ancestors. But the two species of chimpanzee now grouped with the great apes - the common chimp, Pan troglodytes and the bonobo, Pan paniscus - also deserve to be homo members, Wayne State University of Detroit research team leader Dr Morris Goodman said.

The recommendation was supported by Australian geneticist Simon Easteal, of the John Curtin School of Medical Research at the Australian National University, who said "it makes sense, they are very similar to us, in genetic terms".

Such a move would be consistent with the way genetically similar species of bats, rodents and whales have been grouped.

It would also stimulate much needed debate about the rights of these close relatives, Professor Easteal said.

Chimpanzees and humans split from a common ancestor about 5 million to 6 million years ago.

American scientist Jared Diamond, of the University of California, Los Angeles was the first, in 1991, to call for the two to be grouped together, coining the term the third chimpanzee to describe humans.

Professor Easteal made a similar call in 1996, based on his genetic studies showing DNA of chimps and humans was about 98.4 per cent similar. He also said gorillas should be included in the homo genus.

Last year an American study concluded that the DNA of chimps and humans was only 95 per cent similar.

The latest study, published in the Proceedings of the National Academy of Sciences, was based on a comparison of 97 genes. It examined the DNA sequences which were important in making proteins to come up with the figure of 99.4 per cent identical.

Some groups, such as the Great Ape Project, argue apes should have the same legal and moral rights as humans, and not be kept in zoos or used in experiments.

Professor Easteal said it was a difficult issue. Chimpanzees had problems in the wild. "And in good facilities like Taronga Zoo they probably have a reasonable life."

But by emphasising our similarities with chimps, the new research might make people think more.

May 21, 2003

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