Date published: August 17, 2014
Source: University of Utah Health Sciences
http://www.sciencedaily.com/releases/2014/08/140817215846.htm
http://www.sciencedaily.com/releases/2014/08/140817215846.htm
Summary:
A
study led by University of Utah scientists have found a genetic cause for an
adaptation that caused Tibetans to thrive at high altitudes of the Tibetan
Plateau where the air is thin and oxygen is scarce. After a strong reluctance
by the Tibetan people to provide samples for research the team finally obtained
and analysed blood from the people to achieve astounding results. They found
that a gene specifically notated as EGLN1 had been mutated in a single base
pair 8000 years ago and was the cause for this adaptation. They also found that
about 88% of all Tibetans had it and that the mutation was absent in closely
related Asians that lived in the lowlands. They have also identified the
advantages that this mutation provides for carriers like the Tibetans in the particular
habitat. At high altitudes where oxygen is scarce, blood normally thickens with
oxygen carrying blood cells that cause long term effects like heart failure. The Tibetans are protected as the mutation gives
them a decreased response to the low amount of oxygen. Further research that is
being done on this mutation can result in treatments for various diseases.
Relevance:
This
is relevant to what we learnt in class about how in evolution, mutation changes gene pools by adding new traits(characteristics)
that then undergo natural selection, how mutations affect phenotype and also how the mutation is passed on through generations. The Tibetan
people would have originated from the lowland areas which they were normally
adapted to. They probably did not survive very well at high altitude
environment which they were not adapted to, but through natural selection the few people with the gene
mutation would be able to withstand the conditions of scarce oxygen and
reproduce successfully in the new environment. The particular environment favoured
this essential trait and so its frequency increased very quickly and made it
common to most people living there. The mutation affected the gene in the
gametes of people who had the mutation that then caused future offspring to
inherit it. This also shows how a single mutation in the genotype can greatly
change an organism’s phenotype.
Did the research examine Tibet's entire population as a whole, or just the Tibetian populations that lived at the high altitudes?
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DeleteThe entire of Tibet lies on a plateau at an extremely high altitude. So, the research examined Tibet's population as a whole as the entire area is at an unnaturally high altitude for a decent amount of humans to live for a long time, and am almost entirely certain that they did not factor the particularly high peaks differently compared to the regularly high elevation of Tibet.
DeleteYou talked about how the Tibetans have a mutation that helps them thrive at high altitudes. Do people from other high-elevated areas have a similar mutation, like the people of the Alps for example?
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DeleteMy research did not show any similar mutations in high-altitude-living people around the world but it did show that people, like the ones living in the Andes and Ethiopia had similar survival adaptations like the Tibetans that included better respiration systems to live in the high altitude and less oxygen environment. I would think that there can possibly be a particular similarity in the class of genes that are mutated in different people living at high altitudes. Also, to keep in mind is that high altitude regions have different conditions apart from just low oxygen that plays a role in whatever modification they need to live at these heights.
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