Mutation in key gene allows Tibetans to thrive at high altitude

http://www.theguardian.com/science/2010/jul/02/mutation-gene-tibetans-altitude

by lostlogin • 13 years ago

62 23 13 years ago

theguardian.com

lostlogin2• 13 years ago

This is better http://m.sciencemag.org/content/329/5987/72.abstract

sp332• 13 years ago

Why is it better? It doesn't have any of the interviews.

benrapscallion3• 13 years ago

Because it's peer reviewed science and has the data, as opposed to opinions in an interview.

ChuckMcM• 13 years ago

A little gene therapy and voila, a tour de france winner without using any doping! Definitely going to be an interesting time for sports records.

roberthahn2• 13 years ago

Thinking out loud here, as I'm not a physicist or engineer: I wonder if this type of mutation could impact space suit design - would a suit engineered to Tibetan environmental standards (lower pressure, 40% oxygen) for Tibetans, end up being better in other areas? (lighter, more reliable, easier to manoeuvre in)

nether2• 13 years ago

Probably, but it'd only be comfortable for Tibetans. NASA space suits are pressurized to an altitude of 6,000 ft, which is about the same as a commercial airliner cabin. You could loosen that requirement for hardier astronauts, but it'd greatly restrict your astronaut candidate pool.

Crito• 13 years ago

"NASA space suits are pressurized to an altitude of 6,000 ft, which is about the same as a commercial airliner cabin."

This seems to check out, but I am not sure how to reconcile it with astronauts needing to prebreath for a few hours before an EVA (since the ISS atmosphere is comparable to Earth's at sea-level).

From what I can tell most passengers can tolerate up to 8000 feet unpressurized, and although the planes climb fast enough to pop your ears I've certainly never heard of anybody getting the bends.

I think maybe the difference is the difference between oxygen pressure, and the total gas pressure? Space suits (unlike modern spacecraft) use pure oxygen.

roberthahn2• 13 years ago

I agree that it would greatly restrict the candidate pool. My thinking was that if the tradeoffs were significant (and positive) it might change the dynamics of space exploration.

Granted, this isn't likely to come about; I was just thinking out loud.

vrepsys• 13 years ago

Wondering if there could be a genetic test to determine where one should live to achieve optimal health.

nether2• 13 years ago

A gene test for determining susceptibility to AMS was being worked on in 2011: http://online.wsj.com/news/articles/SB1000142405274870336290...

has2k1• 13 years ago

Quickly thinking out aloud.

A probable rule of thumb, if you are not of mixed heritage, do not migrate, stay where the many generations of your ancestors have lived.

If you are of mixed heritage, maybe then that genetic test may do significantly better than any other rule of thumb.

benrapscallion3• 13 years ago

There are probably other loci that provide selective advantage to, in this case, higher altitudes. Without having a rolodex of those, it would be a challenge/highly unlikely to predict phenotypic advantage.

tokenadult2• 13 years ago

"A mutation in the gene that is thought to affect red blood cell production was present in only 9% of the Han population, but was found in 87% of the Tibetan population."

Okay, so according to the news article kindly submitted here, the gene pattern is not invariant in the Tibetan population, nor is it absent from the non-Tibetan population. And this is what we would expect from hundreds of previous studies of human genetics--there is genetic variation within each geographically defined human population, even when the populations are under very strong selection pressure (as here, for this trait). And note too the "thought to affect red blood cell production," as gene mechanisms are still generally very poorly understood.

Way back in the 1970s, I had a student part-time job in the medical school of the University of Minnesota, and one of the physician-professors there then was writing grant applications to try to get to Tibet to study high-altitude adaptations that were presumed to be present in populations that had lived on the high Tibetan Plateau since thousands of years ago. It has taken a long time even to confirm that hypothesis, but already we see that some Tibetans live at high altitude, as their ancestors have for a long time, WITHOUT those gene adaptations. Individual human adaptability is amazing, in many ways even more amazing than the selection pressure on gene assemblages that gives me my white skin (the ancestral human condition was surely dark skin). Human beings can climb Mount Everest without bottled oxygen (please don't try this at home) and humans from whatever ancestral region can live in whatever other region of the world, perhaps in discomfort, but can grow and reproduce there. Human adaptability is quite amazing.

AFTER EDIT: To answer a question I was asked,

Are you pushing in the direction of "Tibetans are indistinguishable from Chinese and Tibet is China"?

No, my answer was not political. (I don't have a Free Tibet bumper sticker on my car, as many of the drivers in this state do, but I'm generally sympathetic with that point of view as to the national sovereignty of historical Tibet, which includes a lot more territory than the current Tibet Autonomous Territory administered by the P.R.C. regime in China.) My statement is biological and VERY general--every genetic study of every geographically defined population in every part of the world finds gene variation in that population, and many of the gene variants found are known to occur in other populations. (Checks for freely downloadable links to post here.)

http://www2.webmatic.it/workO/s/113/pr-1400-file_it-Barbujan...

http://www2.webmatic.it/workO/s/113/pr-1611-file_it-Barbujan...

So, no, even if two populations are all but indistinguishable on genetic grounds (Norway and Sweden come to mind), there may be grounds for distinct national governments, on historical and geographic and cultural grounds, and even if a national population includes substantial genetic diversity within the basic human pattern of all of us being very similar (for example, the United States, or Canada, or Russia, or China), there may be grounds for preserving national unity that groups together substantial genetic diversity. (Again, I must stress that human beings have exceptionally little species-wide genetic diversity, but what diversity they have is found within even narrowly defined geographic populations.) The political issue has nothing to do with the scientific issue of looking for genes.

jhallenworld• 13 years ago

A perhaps interesting side note: when I played around with genetic algorithms it became obvious that initial randomness (or randomness already present in the gene pool) in combination with chromosomal crossover was far more important than other types of mutation for the create of interesting new gene variants.

Anyway, I remember this rule of thumb from somewhere: if a gene gives just a 1% survival advantage, it would take over the population in only 100 generations. It sure seems like this is happening in Tibet.

lostlogin2• 13 years ago

I wonder if the Chinese occupation is having any effect. I could imagine that either ethnic Chinese inflow or native population outflow might make things change. I had a brief google session trying to see if there is any population change recorded, but I didn't get an answer.

pekk• 13 years ago

When you imply that the gene is not distinctive of Tibetans, you are disputing claims I didn't know the article made, and it makes me wonder why. Are you pushing in the direction of "Tibetans are indistinguishable from Chinese and Tibet is China"?

1457389• 13 years ago

Why does this even need to be said? Evolution is the change of allele frequencies over time in a given population. The assumption inherent in that definition is that there are no black and white shifts, it is generally incremental if you assume natural selection is working (codified assumptions included here).

I don't know exactly why your comment annoys me, but I think it has a lot to do with the fact that it "isn't even wrong". You say flowery things like "Human adaptability is quite amazing" and it just emphasizes to me that your thesis about variability is sloppy and vague.

"Gene mechanism" differences definitely exist, and they definitely affect the world around us. At a certain point, "human adaptability" doesn't count for shit. If I am a double APC mutant with abnormal Beta-catenin signalling guess what is overwhelmingly likely to happen to me by age 40? Colorectal carcinoma. Forty or more CAG repeats on an obscure part of chromosome 4? Huntington's, full penetrance. Mutations in my hemoglobin locus? Sickle cell, beta thalassemia and a rogue's gallery of other blood diseases are in my future. "Adaptability" is not a useful concept when these are the problems we face when we inherit genetic diseases. The empirical method has proven that our genes matter for our life outcomes; glossing over this with some handwaving about "adapting" is counterproductive at every level of knowledge.

alixaxel• 13 years ago

There's a documentary (Are We Still Evolving / Through the Wormhole) that explores this and some other cases.

tosseraccount• 13 years ago

The genes are EGLN1 and PPARA

https://en.wikipedia.org/wiki/EGLN1 [EGLN1] is is a ubiquitous, constitutively synthesized transcription factor responsible for upregulating the expression of genes involved in the cellular response to hypoxia.

https://en.wikipedia.org/wiki/Peroxisome_proliferator-activa... PPAR-alpha is a transcription factor and a major regulator of lipid metabolism in the liver. PPAR-alpha is activated under conditions of energy deprivation and is necessary for the process of ketogenesis, a key adaptive response to prolonged fasting.[3]

dschiptsov• 13 years ago

The more simple patterns seem to be overlooked - that banal change in ones breathing patterns - breathe not "deeper" but "more often" - a habit body could learn in two-three days. All the animals, dogs, yaks, etc are doing it.

The key issue is to relax oneself psychologically from the stress of unusual feelings and discomfort (it is almost the same as hangover) and let the body breathe and sleep. Extensive water consumption to boost circulation also helps.

I train groups of tourists a mt. Kailash trek and four days of acclimatization is enough for almost everyone.

I am myself capable of walking the same distances with rates comparable to Tibetans - what kind of genetic mutation I have undergo?)

Mutation in key gene allows Tibetans to thrive at high altitude

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