Shayleigh O’Hanlon – 1
1-2-14
rd
3 Period
Tibetans Live High Life Thanks To Extinct Human
Relatives
I.
Introduction
II.
Tibetan High Life
III.
EPAS1
IV.
Tibetan Genetic Heritage
V.
Gene Therapy
VI.
Conclusion
Tibet is a reasonable sized country that touches China’s border and it is commonly known as
“the roof of the world,” due to its high elevation. People that live in Tibet, called Tibetans,
survive living in the high elevation with help from a gene called EPAS1. The gene helps the
Tibetans survive oxygen deprivation in the high altitudes. Scientists had studied this gene for
years in order to discover its origin, but they didn’t succeed until 2010. They found that the
EPAS1 gene had come from Denisovan DNA. This EPAS1 gene has helped the Tibetans live in
high elevations ever since they inherited the gene from the Denisovan people and we may be
able to use this gene to help people with breathing difficulties.
Tibetans need the EPAS1 gene because Tibet’s altitude rises more than 4,000 meters above
sea level. These heights result in oxygen levels being 40 percent lower than oxygen levels at sea
level. Consequently, such low oxygen levels lead to tremendous stress on the human body
Shayleigh O’Hanlon – 2
1-2-14
rd
3 Period
particularly during pregnancy. The EPAS1 gene is what has help Tibetans survive all the strain
throughout the past years.
Evidently, with help from the EPAS1 gene, Tibetans have been able to endure living at high
elevations. EPAS1 is short for Endothelial PAS Domain Protein 1. According to “EPAS1 gene,”
“The EPAS1 gene, often known as HIF2A, provides instructions for making a protein called
hypoxia-inducible factor 2-alpha (HIF-2α). This protein is one part (subunit) of a larger protein
complex called HIF, which plays a critical role in the body's ability to adapt to changing oxygen
levels”(1). In other words, the EPAS1 gene is what has kept the Tibetans alive in such low
oxygen levels.
Just like the Tibetans, there is another group of people who had the EPAS1 in their DNA,
called the Denisovans. For years, scientists have been trying to find where the EPAS1 gene
originated. They compared stretches of DNA from 40 Tibetan and 40 Han Chines individuals,
but there were only two matches. Then, in 2010, scientist announced that a 41,000 year-old
finger bone, found in Siberia, belonged to a person who was a part of an unknown group of an
extinct society of people. The civilization was named Denisovan, after the name of the cave in
which the fossil was found. The scientists who were studying the EPAS1 decided to compare the
DNA of the finger bone to the DNA of the Tibetans and they matched. This comparison is the
closest scientists have gotten to finding the origin of the EPAS1 gene. Therefore, the chances of
the Tibetans inheriting the EPAS1 gene from the Denisovans are very high. In the end, the
Tibetans must have inherited the EPAS1 gene from the Denisovans and this heritage has helped
the Tibetans live in high elevations for thousands of years.
Shayleigh O’Hanlon – 3
1-2-14
rd
3 Period
In the same way that the EPAS1 gene has helped the Tibetans live in high elevations, we
may be able to use it to help people that have a hard time breathing. Scientists may be able to
extract the gene and place in in the DNA of a person that has difficulty breathing. The person
receiving this gene therapy will be able to breath without needing so much oxygen.
In conclusion, the Tibetans live in high elevations, which results in a need for something that
will assist the human body with the change in oxygen levels. The EPAS1 gene helps with
adapting to the change in oxygen levels. The Tibetans somehow obtained the gene into their
DNA, but scientists did not know how it happened. In 2010, scientists discovered that the
Tibetans and the Denisovans both have the EPAS1 gene. Given this point, scientists theorized
that the Tibetans inherited the gene from the Denisovans. As a result of learning so much about
the EPAS1 gene, scientist may be able to use gene therapy and remove the gene from Tibetan
DNA and place it in another person’s. In this way, we might be able to find a cure for some of
the breathing problems people have.
Shayleigh O’Hanlon – 4
1-2-14
rd
3 Period
References
EPAS1 gene. (2014, December 29). Retrieved January 5, 2015, from
http://ghr.nlm.nih.gov/gene/EPAS1