This release is also in German

Washington D.C. - A new study suggests that chimpanzee subspecies may be more genetically variable than humans and also more closely related to each other--two findings that conflict with some earlier research on chimpanzee genetic diversity. The study's results, reported by a group of German researchers in the 5 November issue of Science, impact on a number of hot topics in evolutionary anthropology, from the origin of modern humans to great ape conservation. The findings also support the idea that cultural differences between chimpanzee populations are probably not the result of genetic variation between these groups.

Although information about variation in the human genome seems to be accumulating at a fast and furious pace, studies of the genetic diversity of the chimpanzee lag well behind. Scientists have managed to glean some information from scattered fragments of the chimpanzee genome, mostly from analysis of mitochondrial DNA. Mitochondrial DNA is separate from the DNA in the cell's nucleus, and appears to be inherited exclusively through the maternal line. The German team, led by Svante Pbo and including Henrik Kaessmann and Victor Wiebe from the Max-Planck-Institute for Evolutionary Anthropology in Leipzig, Germany, decided instead to tap the virtually untouched realm of nuclear DNA variation to get a better look at chimpanzee diversity.

"When we started the study of this sequence," Kaessmann said, "we sat down to think about what a nuclear sequence that would be ideal for answering evolutionary questions should look like." Their target became Xq13.3, a section of the X chromosome that does not code for any proteins, that has a low mutation and recombination rate, and is already well-studied in humans. They sequenced and thoroughly analyzed this bit of DNA from blood taken from the three geographic
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Contact: Heather Singmaster
hsingmas@aaas.org
202-326-6414
American Association for the Advancement of Science
3-Nov-1999