Tibetans adapted to altitude in under 3,000 years

Tibetans took less than 3,000 years to adapt to living at high altitude, said a study published Thursday that could lead to insights on diseases linked to pre-birth oxygen deprivation such as epilepsy.

"This is the fastest genetic change ever observed in humans," said Rasmus Nielsen, a University of California Berkeley biology professor who led the statistical analysis and genome-wide comparison between the Tibetans and the Han Chinese.

According to the study, published in the July 2 issue of Science magazine, the Tibetans and the Han Chinese split into two separate populations some 2,750 years ago, with the larger group moving to the Tibetan plateau where it dwindled while the low-elevation Han expanded dramatically.

The Tibetans, however, quickly evolved a unique ability to live above 4,000 meters (13,000 feet), where oxygen levels are 40 percent lower than those at sea level.

"For such a very strong change, a lot of people would have had to die simply due to the fact that they had the wrong version of a gene," said Nielsen.

Comparing the genes of both ethnic groups, researchers found more than 30 genes with DNA mutations that have become more prevalent in Tibetans than Han Chinese, nearly half of which are related to how the body uses oxygen.

One mutation in particular spread from fewer than 10 percent of the Han Chinese to nearly 90 percent of all Tibetans. It is near a gene called EPAS1, a so-called "super athlete gene" identified several years ago that is associated with improved athletic performance, Nielsen said.

The gene codes for a protein involved in sensing oxygen levels and perhaps balancing aerobic and anaerobic metabolism.

The new findings could steer scientists to still unknown genes that play a role in how the body deals with decreased oxygen, and perhaps explain some diseases, including schizophrenia and epilepsy, associated with oxygen deprivation in the womb, Nielsen said.

"The new finding is really the first time evolutionary information alone has helped us pinpoint an important function of a gene in humans," he added.

Adaptation to low oxygen levels has allowed many peoples, from Andeans to Tibetans, to live at high altitude.

When people from lower elevations move above 4,000 meters they typically tire easily, develop headaches, produce babies with lower birth weights and have a higher infant mortality rate.

Tibetans have none of these problems, despite lower oxygen saturation in the blood and lower levels of hemoglobin levels, which gives blood its red color, and binds and transports oxygen to the body's tissues.

The study used genome data and a large team of researchers from the Beijing Genomics Institute in Shenzhen, China's flagship genome center.

The research was funded by various Chinese, American and Danish organizations.

js/fgf/mlm

Life and Style
ebookNow available in paperback
ebooks
ebookA delicious collection of 50 meaty main courses
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
SPONSORED FEATURES

ES Rentals

    Independent Dating
    and  

    By clicking 'Search' you
    are agreeing to our
    Terms of Use.

    iJobs Job Widget
    iJobs General

    Recruitment Genius: Interactive / Mobile Developer

    £40000 - £45000 per annum: Recruitment Genius: This digital production agency ...

    Recruitment Genius: PHP Developer - Midweight

    £40000 - £45000 per annum: Recruitment Genius: This digital production agency ...

    Recruitment Genius: Junior Front End Developer

    £20000 - £30000 per annum: Recruitment Genius: This digital production agency ...

    Recruitment Genius: Front End Developer - Midweight / Senior

    £35000 - £40000 per annum: Recruitment Genius: This digital production agency ...

    Day In a Page

    Giants Club: After wholesale butchery of Idi Amin's regime, Uganda’s giants flourish once again

    Uganda's giants are flourishing once again

    After the wholesale butchery of Idi Amin's regime, elephant populations are finally recovering
    The London: After 350 years, the riddle of Britain's exploding fleet is finally solved

    After 350 years, the riddle of Britain's exploding fleet is finally solved

    Archaeologists will recover a crucial item from the wreck of the London which could help shed more light on what happened in the vessel's final seconds
    Airbus has patented a jet that could fly from London to New York in one hour

    Airbus has patented a jet that could fly from London to New York in one hour

    The invention involves turbojets and ramjets - a type of jet engine - and a rocket motor
    Tate Sensorium: New exhibition at Tate Britain invites art lovers to taste, smell and hear art

    Tate Sensorium

    New exhibition at Tate Britain invites art lovers to taste, smell and hear art
    10 best sun creams for kids

    10 best sun creams for kids

    Protect delicate and sensitive skin with products specially formulated for little ones
    Ashes 2015: Nice guy Steven Finn is making up for lost time – and quickly

    Nice guy Finn is making up for lost time – and quickly

    He was man-of-the-match in the third Test following his recall to the England side
    Ashes 2015: Remember Ashton Agar? The No 11 that nearly toppled England

    Remember Ashton Agar?

    The No 11 that nearly toppled England
    Turkey-Kurdish conflict: Obama's deal with Ankara is a betrayal of Syrian Kurds and may not even weaken Isis

    US betrayal of old ally brings limited reward

    Since the accord, the Turks have only waged war on Kurds while no US bomber has used Incirlik airbase, says Patrick Cockburn
    VIPs gather for opening of second Suez Canal - but doubts linger over security

    'A gift from Egypt to the rest of the world'

    VIPs gather for opening of second Suez Canal - but is it really needed?
    Jeremy Corbyn dresses abysmally. That's a great thing because it's genuine

    Jeremy Corbyn dresses abysmally. That's a great thing because it's genuine

    Fashion editor, Alexander Fury, applauds a man who clearly has more important things on his mind
    The male menopause and intimations of mortality

    Aches, pains and an inkling of mortality

    So the male menopause is real, they say, but what would the Victorians, 'old' at 30, think of that, asks DJ Taylor
    Man Booker Prize 2015: Anna Smaill - How can I possibly be on the list with these writers I have idolised?

    'How can I possibly be on the list with these writers I have idolised?'

    Man Booker Prize nominee Anna Smaill on the rise of Kiwi lit
    Bettany Hughes interview: The historian on how Socrates would have solved Greece's problems

    Bettany Hughes interview

    The historian on how Socrates would have solved Greece's problems
    Art of the state: Pyongyang propaganda posters to be exhibited in China

    Art of the state

    Pyongyang propaganda posters to be exhibited in China
    Mildreds and Vanilla Black have given vegetarian food a makeover in new cookbooks

    Vegetarian food gets a makeover

    Long-time vegetarian Holly Williams tries to recreate some of the inventive recipes in Mildreds and Vanilla Black's new cookbooks