Research conducted more 65 years ago by a team of scientists led by Sir Ronald Aylmer Fisher, the eminent British statistician and geneticist, concluded that this gene variant was the same in humans and chimpanzees and existed throughout time--an example of balancing selection. Their findings were published in 1939 in "Nature," one of the world's leading science journals.
A new team of researchers, including Anne Stone, an anthropological geneticist at Arizona State University, writes in the cover story of this week's "Nature" (April 13, 2006), that while the observations made by Fisher and his team were accurate, "their explanation was wrong." Instead of being an example of balancing selection, the researchers conclude that both humans and chimpanzees have gene variants but for different reasons--and is an example of convergent evolution.
It was only a few years ago, in 2003, that sensitivity to a bitter compound known as phenylthiocarbamide (PTC) was mapped in human genes.
"That gene was found to be controlling whether you can taste PTC or not," says Stone, an associate professor in ASU's School of Human Evolution and Social Change in the College of Liberal Arts and Sciences.
"We decided to look at this in chimpanzees and see if Fisher was right," she says. The "we" includes authors of the report Stephen Wooding, Michael T. Howard, Diane M. Dunn, Robert B. Weiss and Michael J. Bamshad in the Department of Human Genetics at the University of Utah; Bernd Bufe and Wolfgang Meyerhof of the German Institute of Human Nutrition Postdam-Rehbruecke; and Christina Grassi and Maribel Vazquez
Source:Arizona State University