Researchers Solve Questions About Ethiopians` High-Altitude Adaptations
Baku, July 5 (AZERTAC). Over many generations, people living in the high-altitude regions of the Andes or on the Tibetan Plateau have adapted to life in low-oxygen conditions. Living with such a distinct and powerful selective pressure has made these populations a textbook example of evolution in action, but exactly how their genes convey a survival advantage remains an open question. Now, a University of Pennsylvania team has made new inroads to answering this question with the first genome-wide study of high-altitude adaptations within the third major population to possess them: the Amhara people of the Ethiopian Highlands.
Surprisingly, all three groups' adaptations appear to involve different genetic mutations, an example of convergent evolution.
"These three groups took different genetic approaches to solving the same problem," said senior author Sarah Tishkoff, a Penn Integrates Knowledge professor with appointments in the genetics department in Penn's Perelman School of Medicine and the biology department in the School of Arts and Sciences.
In addition to Tishkoff, the research was led by Laura B. Scheinfeldt, a research scientist in the genetics department at the Perelman medical school. Other members of the genetics department who contributed to the research are Sameer Soi, Simon Thompson, Alessia Ranciaro, William Beggs, Charla Lambert and Joseph P. Jarvis.
The Penn team collaborated with Dawit Wolde Meskel, Dawit Abate and Gurja Belay of the Department of Biology of Addis Ababa University.
Pregnant women are especially susceptible to the physiological pressure represented by hypoxia, which influences the birth weight and health of their children. Yet people have been living in the high-altitude regions of the Andes and the Tibetan Plateau for generations, with little apparent ill effect.
Anthropologists, notably, Cynthia Beall, of Case Western University, and Lorna Moore, of Wake Forest University, have therefore extensively documented their physiological traits, trying to understand how these groups offset the problems pregnant women would normally have in hypoxic environments. More recently, geneticists have attempted to correlate these physical traits, or phenotypes, with the genes that are responsible for them, or genotypes.
Researchers have long wanted to add additional populations for comparison, and while the people of the Ethiopian Highlands met the criteria, living at over 3,000 meters above sea level, economic, linguistic and geographic hurdles stood in the way of collecting the data.
This research was supported by funding from the National Institutes of Health and the National Science Foundation.
Other news in this section
