Tibetans Developed Genes to Help Them Adapt to Life at High Elevations

[The Straight Story]

Tibetans Developed Genes to Help Them Adapt to Life at High Elevations

ScienceDaily (May 15, 2010) — Researchers have long wondered why the people of the Tibetan Highlands can live at elevations that cause some humans to become life-threateningly ill -- and a new study answers that mystery, in part, by showing that through thousands of years of natural selection, those hardy inhabitants of south-central Asia evolved 10 unique oxygen-processing genes that help them live in higher climes.

In a study published May 13 in Science Express, researchers from the University of Utah School of Medicine and Qinghai University Medical School in the People's Republic of China report that thousands of years ago, Tibetan highlanders began to genetically adapt to prevent polycythemia (a process in which the body produces too many red blood cells in response to oxygen deprivation), as well as other health abnormalities such as swelling of the lungs and brain (edema) and hypertension of the lung vessels leading to eventual respiratory failure. Even at elevations of 14,000 feet above sea level or higher, where the atmosphere contains much less oxygen than at sea level, most Tibetans do not overproduce red blood cells and do not develop lung or brain complications. The Utah and Chinese researchers found evidence that this might be related to at least 10 genes, two of which are specific genes strongly associated with hemoglobin, a molecule that transports oxygen in the blood.

High-altitude lung and brain complications threaten and even kill mountaineers who scale the world's tallest peaks. Others who find themselves at elevations significantly higher than where they normally live and work also can be stricken with the condition. Adaptations to living at higher altitudes have occurred in humans more than once, such as with people indigenous to the Andes Mountains in South America and people native to high altitude regions in the Ethiopian mountains in Africa. But the Tibetans have evolved genes that others living at similar elevations have not developed, according to Lynn B. Jorde, Ph.D., professor and chair of human genetics at the U of U School of Medicine and a senior author on the study. "For the first time, we have genes that help explain that adaptation," Jorde said.

http://www.sciencedaily.com/releases/2010/05/100513143453.htm

[aquart]

1. So the rest of us would be wise to stay away from those mountains?

What happens to Tibetans who try to live in lowlands?

[sandnsea]

2. Way cool, thanks! n/t

[JCMach1]

3. Very cool... seems evolution is faster than some scientists would have thought

All of the recent hominid finds, the neanderthal DNA study, all seem to support this. Makes you wonder what new genes are being hard-wired as people copulate around the world at this very second.

[diane in sf]

4. It appears that there is sensing apparatus in our DNA that puts pressure to mutate

on the parts of the genome that need to change to help adaptation to new environments. Sorry no links, but I was reading about this somewhere recently.

[JCMach1]

5. Remember the changed color of moths in industrial england that was always used as an example of

natural selection.

What if instead it was actually genes switching on and off to adapt to the environment?

Looks like we are still taking our first baby steps to fully understand DNA.

[Odin2005]

7. Over short periods natural selection happens very quick.

Periods of "stasis" are really better described as evolutionary zig-zagging, as populations adapt back and forth to short-term fluctuations (like climate cycles and epidemics of infectious diseases) but there being no net change over longer periods. This is the basis of the concept of "Punctuated Equilibrium". When there is a permanent long-term change in the environment natural selection goes to work and turns one of the little zigs or zags into a substantial change.

[Happyhippychick]

6. So evolution really works? Better tell all of the 'pube candidates!

[applegrove]

8. LOL!