Cynthea Beall | |
---|---|
Born | 1949 |
Nationality | American |
Citizenship | United States |
Alma mater | Pennsylvania State University |
Known for | High-altitude adaptation in humans |
Awards | See text |
Scientific career | |
Fields | Anthropology Human evolution |
Institutions | Case Western Reserve University |
Thesis | The Effects of High Altitude on Growth, Morbidity and Mortality of Peruvian Infants |
Cynthia Beall is an American physical anthropologist at the Case Western Reserve University, Cleveland, Ohio. Four decades of her research on people living in extremely high mountains became the frontier in understanding human evolution and high-altitude adaptation. Her groundbreaking works among the Andean, Tibetan and East African highlanders are the basis of our knowledge on adaptation to hypoxic condition and how it influences the evolutionary selection in modern humans. She is currently the Distinguished University Professor, and member of the U.S. National Academy of Sciences and the American Philosophical Society. [1]
Cynthia M. Beall completed a BA in biology from the University of Pennsylvania in 1970. She entered Pennsylvania State University to obtain MA in anthropology in 1972, and PhD in anthropology in 1976.
She joined the faculty of the Department of Anthropology at the Case Western Reserve University as assistant professor in 1976. She became an associate professor in 1982 and a full Professor in 1987. [2] She was designated the S. Idell Pyle Professor of Anthropology 1994, and the Distinguished University Professor in 2010.
She had served as President-elect, President, and Past-President of the Human Biology Council (now Human Biology Association) from 1991 to 1995. She was the Chair-elect of the Section on Anthropology of the American Association for the Advancement of Science (AAAS) in 1995 and 2010. She was the Chair (2002-2005) of Section 51 Anthropology, Councilor (2002-2005), and Chair (2011) of Nominating Committee of the US National Academy of Sciences. She hold the Chair (2001-2003) of the US National Committee for the International Union of Biological Sciences. [3]
Cynthia Beall is the leading scientist in the study of high-altitude adaptation in humans, particularly in places where there is little air to breathe. Among the Tibetans the first thing that she discovered was that they could live at high levels without having high hemoglobin concentrations or large chests, they had high birth-weighted babies, and no complications of mountain sickness. Unlike most humans who migrate to high altitude, the Tibetans do not exhibit the elevated haemoglobin concentrations to cope up with oxygen deficiency, but they inhale more air with each breath and breathe more rapidly, and retain this unusual breathing and elevated lung-capacity throughout their lifetime. [4] [5] Their high levels (mostly double) of nitric oxide in the blood increase their blood vessels to dilate for enhanced blood circulation. [6] An astonishing discovery of Beall is the convergent evolution in humans from her studies on other highlanders such as the Amhara in the high-plateau regions of northwest Ethiopia, the Omro people in the southwest Ethiopia, and the Aymara of the American Andes. She found that these groups had adapted to low oxygen environment very differently from the Tibetans. [1] [7] Physiological conditions such as resting ventilation, hypoxic ventilatory response, oxygen saturation, and haemoglobin concentration are significantly different between the Tibetans and the Aymaras. [8] The Amharans exhibit elevated haemoglobin levels, like Andeans and lowlander peoples at high altitudes, while the Andeans have increased haemoglobin level like normal people in the highlands. [9] All these observations show that different people adapted to high altitude in different genetic and physiological responses. [10]
Hemoglobin is a protein containing iron that facilitates the transport of oxygen in red blood cells. Almost all vertebrates contain hemoglobin, with the exception of the fish family Channichthyidae. Hemoglobin in the blood carries oxygen from the respiratory organs to the other tissues of the body, where it releases the oxygen to enable aerobic respiration which powers the animal's metabolism. A healthy human has 12 to 20 grams of hemoglobin in every 100 mL of blood. Hemoglobin is a metalloprotein, a chromoprotein, and globulin.
The bar-headed goose is a goose that breeds in Central Asia in colonies of thousands near mountain lakes and winters in South Asia, as far south as peninsular India. It lays three to eight eggs at a time in a ground nest. It is known for the extreme altitudes it reaches when migrating across the Himalayas.
The Tibetan people are an East Asian ethnic group native to Tibet. Their current population is estimated to be around 6.7 million. In addition to the majority living in Tibet Autonomous Region of China, significant numbers of Tibetans live in the Chinese provinces of Gansu, Qinghai, Sichuan, and Yunnan, as well as in India, Nepal, and Bhutan.
Polyandry is a marital arrangement in which a woman has several husbands. In Tibet, those husbands are often brothers; "fraternal polyandry". Concern over which children are fathered by which brother falls on the wife alone. She may or may not say who the father is because she does not wish to create conflict in the family or is unsure who the biological father is. Historically the social system compelled marriage within a social class.
Chronic mountain sickness (CMS) is a disease in which the proportion of blood volume that is occupied by red blood cells increases (polycythaemia) and there is an abnormally low level of oxygen in the blood (hypoxemia). CMS typically develops after extended time living at high altitude. It is most common amongst native populations of high altitude nations. The most frequent symptoms of CMS are headache, dizziness, tinnitus, breathlessness, palpitations, sleep disturbance, fatigue, loss of appetite, confusion, cyanosis, and dilation of veins.
The Changtang is a part of the high altitude Tibetan Plateau in western and northern Tibet extending into the southern edges of Xinjiang as well as southeastern Ladakh, India, with vast highlands and giant lakes. From eastern Ladakh, the Changtang stretches approximately 1,600 kilometres (990 mi) east into Tibet as far as modern Qinghai. The Changtang is home to the Changpa, a nomadic Tibetan people. The two largest settlements within the Tibetan Changtang are Rutog Town the seat of Rutog County and Domar Township the seat of Shuanghu County.
The effects of high altitude on humans are mostly the consequences of reduced partial pressure of oxygen in the atmosphere. The medical problems that are direct consequence of high altitude are caused by the low inspired partial pressure of oxygen, which is caused by the reduced atmospheric pressure, and the constant gas fraction of oxygen in atmospheric air over the range in which humans can survive. The other major effect of altitude is due to lower ambient temperature.
Fabiola León-Velarde Servetto is a Peruvian physiologist who has devoted her research to the biology and physiology of high altitude adaptation. Born in Lima, Peru. She is the daughter of Carlos Leon-Velarde Gamarra and Juana Servetto Marti from Uruguay, and granddaughter of Angelica Gamarra. Under the mentorship of high altitude physiologist Carlos Monge Cassinelli, she obtained a BSc. in Biology (1979), an MSc (1981) and DSc (1986) in physiology at Cayetano Heredia University in Lima, Perú.
Endothelial PAS domain-containing protein 1 is a protein that is encoded by the EPAS1 gene in mammals. It is a type of hypoxia-inducible factor, a group of transcription factors involved in the physiological response to oxygen concentration. The gene is active under hypoxic conditions. It is also important in the development of the heart, and for maintaining the catecholamine balance required for protection of the heart. Mutation often leads to neuroendocrine tumors.
Melvyn C. Goldstein is an American social anthropologist and Tibet scholar. He is a professor of anthropology at Case Western Reserve University and a member of the National Academy of Sciences.
A. Roberto Frisancho is a biological anthropologist and the Arthur F. Thurnau Professor of Anthropology at the University of Michigan. He is the 2008 recipient of the Franz Boas Distinguished Achievement Award in Anthropology bestowed by the American Human Biology Association. He is best known for his work on developmental human adaptation to extreme environments such as high altitudes, growth, anthropometry and evaluation of nutritional status. Specifically, he advanced the hypothesis and demonstrated that the origin of adult variability of biological phenotypic traits are function of the effects and adaptations to environmental conditions that the organism makes during the developmental stage. Within this conceptual framework, he has contributed numerous papers on bioenergetics, the nutrition and developmental determinants of pre-natal and post-natal growth including teenage pregnancy. In 2013, he received the Charles Darwin Lifetime Achievement Award bestowed by the American Association of Physical Anthropologists.
Mark S. Aldenderfer is an American anthropologist and archaeologist. He is the MacArthur Professor of Anthropology at the University of California, Merced where he was previously the Dean of the School of Social Sciences, Humanities, and Arts. He has served as Professor of Anthropology at the University of Arizona, and the University of California, Santa Barbara. Aldenderfer received his Ph.D. from Penn State University in 1977. He is known in particular for his comparative research into high-altitude adaptation, and for contributions to quantitative methods in archaeology. He has also served as editor of several journals in anthropology and archaeology.
Hypoxic ventilatory response (HVR) is the increase in ventilation induced by hypoxia that allows the body to take in and transport lower concentrations of oxygen at higher rates. It is initially elevated in lowlanders who travel to high altitude, but reduces significantly over time as people acclimatize. In biological anthropology, HVR also refers to human adaptation to environmental stresses resulting from high altitude.
The Hyolmo are a people mainly from the Eastern and Northern Himalayan Regions of Nepal called Helambu. They refer to themselves as the "'hyolmowa" or "hyolmopa" and are native residents of the Helambu valleys(Melamchigyang, Nakote, Tarkegyang, Sermathang) and the surrounding regions of Northeastern Nepal. The combined population in these regions is around 11,000. They also have sizeable communities in Bhutan, Darjeeling, Sikkim and some regions of South-Western Tibet. They are among the 59 indigenous groups officially recognized by the Government of Nepal as having a distinct cultural identity and are also listed as one of the 645 Scheduled Tribes of India.
Yak butter is butter made from the milk of the domestic yak. Many herder communities in China, India, Mongolia, Nepal, Gilgit-Baltistan Pakistan and Tibet produce and consume dairy products made from yak's milk, including butter. Whole yak's milk has about twice the fat content of whole cow's milk, producing a butter with a texture closer to cheese. It is a staple food product and trade item for herder communities in south Central Asia and the Tibetan Plateau.
Organisms can live at high altitude, either on land, in water, or while flying. Decreased oxygen availability and decreased temperature make life at such altitudes challenging, though many species have been successfully adapted via considerable physiological changes. As opposed to short-term acclimatisation, high-altitude adaptation means irreversible, evolved physiological responses to high-altitude environments, associated with heritable behavioural and genetic changes. Among vertebrates, only few mammals and certain birds are known to have completely adapted to high-altitude environments.
Paul Thornell Baker was Evan Pugh Professor Emeritus of Anthropology at the Pennsylvania State University, and was “one of the most influential biological anthropologists of his generation, contributing substantially to the transformation of the field from a largely descriptive to a hypothesis-driven science in the latter half of the 20th century. He pioneered multidisciplinary field science, firmly established a place for biological anthropology and human population biology in national and international science, and trained a host of graduate students in good science, who, in turn, continued his commitment to collaborative research.”
High-altitude adaptation in humans is an instance of evolutionary modification in certain human populations, including those of Tibet in Asia, the Andes of the Americas, and Ethiopia in Africa, who have acquired the ability to survive at altitudes above 2,500 meters. This adaptation means irreversible, long-term physiological responses to high-altitude environments associated with heritable behavioral and genetic changes. While the rest of the human population would suffer serious health consequences at high altitudes, the indigenous inhabitants of these regions thrive in the highest parts of the world. These humans have undergone extensive physiological and genetic changes, particularly in the regulatory systems of oxygen respiration and blood circulation when compared to the general lowland population.
Sarah Anne Tishkoff is an American geneticist and the David and Lyn Silfen Professor in the Department of Genetics and Biology at the University of Pennsylvania. She also serves as a director for the American Society of Human Genetics and is an associate editor at PLOS Genetics, G3, and Genome Research. She is also a member of the scientific advisory board at the David and Lucile Packard Foundation.
Thelma Shoher Baker was an American educator and anthropologist, on the faculty of the Pennsylvania State University from the 1970s until her retirement in 1986.