Anthropology 130 Research Simulation 2

Preparing to go to Tibet
 50 points total

Instructions

This assignment will go over how biological adaptations can allow people to survive in

high altitude environments. Just as there are different ways that people have adapted to

hot and cold environments, people living in high altitudes today possess traits that allow

them to thrive where others would have a very hard time.

A section at the Understanding Evolution website describes what anthropologists have

found when studying a group of Tibetans who were apparently adapted to high altitude

living. The webpage contains both text and video interviews explaining the concept. This

week’s assignment involves thinking about this case study and linking it to what we

have learned.

Type your answers into the separate answer sheet, which is just a list of numbers.

Answers can be incomplete sentence unless otherwise stated in the question.

Assignment Start

Fresh from your trip to the Philippines, you run into your anthropology instructor! He

wants your help on a research project:

“It’s great that I ran into you since you know about anthropology. I am working on a

study of human biological adaptation to hypoxia at high altitude. While we have cultural

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adaptations today, such as oxygen tanks, people who have traditionally lived in high

altitude have picked up biological traits from natural selection that give them an

advantage in that extreme environment.” Thinking that this is a great way to get another

adventure under your belt, you keep listening.

Part One – Hypoxia and Acclimatization

Your instructor continues: “I actually have experience traveling to a high elevation area

during my studies. During one trip to Perú to conduct a study on ancient human health

and disease, I had some spare time to see the wonderful country. I wanted to see

Machu Picchu and Cusco, which is 11,150 feet above sea level. When I was planning

the trip, I received a lot of advice about adjusting to the altitude. One thing that I heard

was that I should never run or even walk fast on the first day there.”

You feel that you should reply and continue the conversation: answer the following

questions based on the lecture or textbook material on hypoxia. You can also search the

Internet, but you have to phrase the answer in your own way and you are responsible

for the trustworthiness of the information you find.

1. How does hypoxia harm the body? Answer in at least one sentence. (2 points)

Your instructor welcomes your response and continues his story: “I flew to Cusco and

made an effort to not exert myself. The air really did feel thinner than I was used to!

After a few days, I felt that I could be more active, though I still could not run.”

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2. What biological acclimatizations did your instructor’s body activate to adjust to the high altitude to make him feel a little better? Answer in at least one sentence. (2 points)

“Yeah, you get it! Giving myself time to adapt to the environment resulted in a great trip

to the Andes mountains. I even made it to Machu Picchu, one of the UNESCO World

Heritage Sites and a gorgeous location.” Your instructor pulls out his phone and flips

through his photos before showing one to you. “This is me at Machu Picchu!”

{ Caption: “I still have those boots!” }

“When I returned to sea level, my adaptations made me more physically able for a little

while. I could exert myself like I have never done before. It was like having

superpowers! My adaptations faded, though, since they were temporary by definition.”

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Part Two – Hypoxia and Genetic Adaptations

You agree to help your instructor’s research project. “I’ve heard that studies of native

Tibetan populations have found some evidence of biological adaptations. My own

undergraduate school, U.C. Berkeley, has a write-up of these findings as part of their

Understanding Evolution website. (Fun fact: I took an undergraduate class with the

researcher in charge of that site, Dr. Roy Caldwell.) Could you go there and tell me what

you find?” Ready to get to work, you find a computer and go to the website that your

instructor suggested:

A. Go the webpage “Evolving altitude aptitude” in the Understanding Evolution site at

the following address: http://evolution.berkeley.edu/evolibrary/news/101001_altitude

B. Read the text, but stop before the “Discussion and extension questions” section. I

have my own questions! You can also watch the videos, but they are not required for

these questions.

C. Answer the following questions. Direct answers can be found in the article, so don’t

look in other sites.

The “Evolving altitude aptitude” article mentions that the Tibetans are genetically

adapted to high altitude since their population have lived in that environment for

thousands of years.

3. At approximately what altitude do Tibetans live? (1 point)

4. What do the bodies of the Tibetans do to adapt to the thinner air that is not seen in other people? (2 points)

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Researchers conclude that a certain allele in a gene called EPAS1 allows the Tibetans

to adapt to high altitude compared to the low altitude-living Han Chinese nearby.

5. For all people, the EPAS1 gene codes for a protein that does what for the human body? (2 points)

6. How many years ago did the Tibetan and Han Chinese lineages separate, leading to different genetic trajectories? (1 point)

Since the article was first written, a new discovery has added more knowledge about

the Tibetan EPAS1 allele. This discovery is described in a 2014 update inside a blue

box on the webpage. The update gives us a glimpse into future lecture topics on human

ancestors.

7. What is the name of the ancient human group that also had the Tibetan hypoxia- adapted EPAS1 allele? (2 points)

8. Where did this ancient human live? And around how many years ago did they live? Look for the specific answers! (2 points)

9. Based on the updated information, what is the researchers’ explanation of how the prehistoric ancestors of Tibetans first got the hypoxia-adapted EPAS1 allele? (2 points)

Part Three – Allele Frequencies

You start to see how the course topics are connected to each other. Wanting to learn

more, you search on Google Scholar to learn more about Tibetan adaptations to

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hypoxia. A paper by Xin Yi and over twenty other authors (!!) (2011) has data on EPAS1

allele frequencies in the Tibetan and Han populations. The researchers found that the

frequency of the hypoxia-adapted allele in Tibetans is 0.87. You remember that the

frequency scale goes from 0.0 to 1.0, with 0.0 meaning the allele is not there at all, and

1.0 meaning that everyone has the same allele.

10. If the frequency of the hypoxia-adapted allele in Tibetans is 0.87, then what is the

frequency of the non-hypoxia-adapted allele in Tibetans? For a gene with two

alleles, the frequency of one allele equals 1.0 minus the frequency of the other

allele. (2 points)

11. In the Tibetan population, is the hypoxia-adapted EPAS1 allele more common, or is

the non-hypoxia-adapted allele more common? (1 point)

The Yi paper states that the Han Chinese allele frequencies are 0.10 for the hypoxia-

adapted EPAS1 allele and 0.90 for the non-hypoxia-adapted allele.

12. Which EPAS1 allele is more common in the Han Chinese population, hypoxia-

adapted or non-hypoxia-adapted? (1 point)

13. Based on these results, do you think that gene flow between the Tibetans and Han

Chinese is high or low? (1 point)

The different allele frequencies between Tibetans and Han shows that the hypoxia-

adapted allele is far more common in Tibetans due to the natural selection spreading

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that allele where it is an adaptation. Outside of Asians, no one has the hypoxia-adapted

EPAS1 allele.

14. What is the number for the frequency of the hypoxia-adapted allele outside of Asia,

based on the above sentence? (2 points)

Part Four – Connections to the Course

You have a good sense of the research on Tibetan adaptation to hypoxia. Satisfied, you

take a short break, but you keep thinking of the discoveries about modern Tibetans. A

lot of the things you learned tie back to what you learned in class. You feel it would be

good to show your instructor these connections in your report. Finishing your break and

feeling refreshed, you get back to writing.

This section has more questions that build off of the article on Tibetan high altitude

adaptation, but are answered using material from the lectures and textbook. The goal is

to form connections across the topics we have learned in class, in order to remember

everything more concretely. The general topic is given for each question to give you a

lead on finding the answer.

15. Genetics: It is confusing that genes and proteins are given the same name, such as EPAS1. Let’s sort them out with the basics. A gene is a section of what type of molecule? (2 points)

16. Genetics: When a gene is used by an organism, the instructions are first transcribed into mRNA, which is then translated into a chain of what other type of molecule as the final step in synthesis? (2 points)

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The article was focused mostly on genetics. Another way to study Tibetan high altitude

adaptation is to measure their actual lung power and compare them to the Han

Chinese. A new study found that Tibetans had larger and more powerful lungs than the

Han Chinese (Weitz, Garruto, and Chin, 2016). Interestingly, Tibetans must have

developed their more-powerful lungs in their adolescent period since Tibetan and Han

had the same lung power from infancy through the juvenile period.

17. Life History: What is the life history period that spreads new hormones through the body, causing new developments in adolescence? (2 points)

18. Life History: Why is it extremely unlikely for people to develop powerful lungs after the adolescent period? (2 points)

Researchers are still studying the Tibetans to learn more about their biological

adaptations to hypoxia. Anthropologists are also studying the indigenous people of the

Andes Mountains to compare and contrast their biological adaptations with the Tibetans.

Part Five – Textbook Nutrition

Working with allele frequencies was rewarding, but also very tiring. You start to get

hungry, but can’t decide what to eat. For inspiration about essential nutrients, you open

the textbook Essentials of Physical Anthropology by Clark Spencer Larsen. You start

reading at the section “Nutritional Adaptation” and quiz yourself as you go to make sure

that you understand the main points.

19. According to the textbook, what are two consequence of being undernourished? (2

points)

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20. Based on James Neel’s research, why would a “thrifty genotype” be an adaptation

for prehistoric Native Americans? Answer in at least a whole sentence in your own

words. (3 points)

21. Why would the “thrifty genotype” now be maladaptive in modern times? Think of the

change in environment from prehistoric times to today. Answer in at least a whole

sentence in your own words. (3 points)

Part Six – Thinking About Blood

Not feeling particularly hungry anymore, you put the textbook away and go out to get a

little exercise. You recall how the adaptation to hypoxia in the “Evolving altitude

aptitude” article involved the blood of Tibetans. As you work up a sweat and raise your

pulse, you realize that the topic of blood has appeared in several lectures.

22. Thinking about other types of human adaptation, how is blood flow controlled by the

body in response to an extremely hot environment or to overexerting yourself? (1

point)

23. How is blood flow controlled in an extremely cold environment? (1 point)

24. One lecture described the ABO blood system. With at least a whole sentence,

explain why someone with O blood is a universal donor. Incorporate the word

‘antigen’ correctly in your explanation. (3 points)

“Hey, you! Are you there?”

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Startled back to your surroundings, you see a good friend peering at you and waving

her hand side-to-side at your face.

“Funny running into you here. Looks like you’re working out too! Hey, you are taking

anthropology. I have a question: I heard that I should eat a diet of mainly dairy products

because I have B type blood. Do you know anything about whether the ‘Blood-Type’ diet

has any scientific research supporting it?” You promise to look up some information.

Back at home, you find a news story from a science website about a team that

scientifically tested the ABO blood-type diet. You email your friend back with information

based on that news story:

A. Go the webpage “Theory behind popular blood-type diet debunked” in the

ScienceDaily site at the following address: https://www.sciencedaily.com/

releases/2014/01/140115172246.htm

B. Read the full story.

C. Write a short paragraph of a few complete sentences that explains the research

to your friend.

25. In a single short paragraph, address the following questions:

A. What is the name of the popular book that started the ABO Blood Type diet idea,

and who is the book’s author? (2 point)

B. Is there evidence that people with different blood types should eat different types

of foods to improve their health? (2 points)

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C. What types of diets do the researchers recommend to help all people, regardless

of blood type? (2 points)

Hint: start with a thesis statement introducing the topic, such as “I read a news story that

tested the ‘Blood-Type’ diet and made some conclusions.”

The next day, an email arrives in your inbox. “You really learned a lot in that class! Well,

I won’t keep you. Thanks for the info!” Feeling satisfied from helping your friend, you

wrap up the work you have done.

Conclusion

You turn in all of the information you found to your very grateful instructor. “Wow, you

went above and beyond with the connections that you made. This will help a lot as I try

to get funding to go study the Tibetans on their home turf.” He takes a deep breath: “I

hope my lungs are ready!” He runs off to the associate instructor offices.

Be sure to have answered every question in the answer sheet. Please submit the report

sheet under the assignment link in Canvas or hand in a paper copy in class.

References (to the real research featured here if you want more) Wang, J., García-Bailo, B., Nielsen, D. E., & El-Sohemy, A. (2014). ABO genotype, ‘blood-type’ diet and cardiometabolic risk factors. PLoS ONE, 9(1), e84749.

Weitz, C. A., Garruto, R. M. and Chin, C.-T. (2016), Larger FVC and FEV1 among Tibetans compared to Han born and raised at high altitude. Am. J. Phys. Anthropol., 159: 244–255.

Yi, X., Liang, Y., Huerta-Sanchez, E., Jin, X., Cuo, Z. X., Pool, J. E., . . . Wang, J. (2010). Sequencing of 50 human exomes reveals adaptation to high altitude. Science, 329(5987), 75-8.

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