Professor Beall is a biological anthropologist whose research focuses on human adaptation to high-altitude hypoxia, particularly the different patterns of adaptation exhibited by Andean, Tibetan, and East African highlanders. Her current research deals with the genetics of adaptive traits and evidence for natural selection, with the role of nitric oxide in oxygen delivery at high altitudes and with the biological, socio-cultural, and public health determinants of reproduction and survival at high altitudes. She teaches courses on human evolution, human biology, and evolutionary medicine Professor Beall is a member of the U.S. National Academy of Sciences, American Philosophical Society, and the American Academy of Arts and Sciences. https://anthropology.case.edu/faculty/cynthia-beall/ Phone: 216 368 2277 Address: Case Western Reserve University Anthropology Department Cleveland, OH 44106
Populations residing for millennia on the high-altitude plateaus of the world started natural exp... more Populations residing for millennia on the high-altitude plateaus of the world started natural experiments that we can evaluate to address questions about the processes of evolution and adaptation. A 2001 assessment in this journal summarized abundant evidence that Tibetan and Andean high-altitude natives had different phenotypes, and the article made a case for the hypothesis that different genetic bases underlie traits in the two populations. Since then, knowledge of the prehistory of high-altitude populations has grown, information about East African highlanders has become available, genomic science has grown exponentially, and the genetic and molecular bases of oxygen homeostasis have been clarified. Those scientific advances have transformed the study of high-altitude populations. The present review aims to summarize recent advances in understanding with an emphasis on the genetic bases of adaptive phenotypes, particularly hemoglobin concentration among Tibetan highlanders. EGLN1 and EPAS1 encode two crucial proteins contributing to oxygen homeostasis, the oxygen sensor PHD2 and the transcription factor subunit HIF-2α, respectively; they show signals of natural selection such as marked allele frequency differentiation between Tibetans and lowland populations. EPAS1 genotypes associated in several studies with the dampened hemoglobin phenotype that is characteristic of Tibetans at high altitude but did not associate with the dampened response among Amhara from Ethiopia or the vigorous elevation of hemoglobin concentration among Andean highlanders. Future work will likely develop understanding of the integrative biology leading from genotype to phenotype to population in all highland areas.
Women in a Tibetan speaking population living at 3250-3560 m in Upper Chumik, Nepal, have median ... more Women in a Tibetan speaking population living at 3250-3560 m in Upper Chumik, Nepal, have median ages at menopause and menarche of 46.8 and 16.2 years, respectively, assessed by the status quo technique. Recalled ages at menopause and menarche yield similar results and suggest a long-term existence of a pattern of relatively accelerated age at menopause and delayed age at menarche. Variation in the length of the calculated biological reproductive span in this sample is more strongly associated with recalled age at menopause than recalled age at menarche. The age at menopause in Upper Chumik is accelerated relative to that reported for Western industrial populations; however, these data do not permit drawing conclusions about the reasons underlying the acceleration.
... Cynthia M. Beall Department of Anthropology, Case Western Reserve University, Cleveland, OH 4... more ... Cynthia M. Beall Department of Anthropology, Case Western Reserve University, Cleveland, OH 441067125 USA ... Beall, CM, LA Almasy, J. Blangero, S. Williams-Blangero, GM Brittenham, KP Strohl, M. Decker, L. Vargas, M. Villena, R. Soria, A. Alarcon, and C. Gonzales. ...
▪ The high-altitude Andean and Tibetan Plateaus offer natural experimental settings for investi... more ▪ The high-altitude Andean and Tibetan Plateaus offer natural experimental settings for investigating the outcome of the past action of evolution and adaptation as well as those ongoing processes. Both Andean and Tibetan high-altitude natives are descended from sea-level ancestors; thus both initially encountered chronic, lifelong high-altitude hypoxia with the same homeostatic “toolbox” that evolved at sea level for responding to brief and transient hypoxia. Yet now they differ phenotypically in many traits thought to be important for offsetting chronic high-altitude hypoxia. Compared on the basis of mean values of five traits, the characteristics of Tibetan high-altitude natives differ more than those of Andean high-altitude natives from the ancestral or unselected response to chronic hypoxia exhibited by acclimatized lowlanders. This suggests that different evolutionary processes have occurred in the two geographically separate areas, although it is not clear why or how those processes differed. Answers to those questions require better knowledge of the prehistory of human populations on the plateaus, as well as information on new phenotypes and the relationship between phenotype and genotype.
The Himalayas and adjoining slopes and plateaus represent a unique setting for addressing a numbe... more The Himalayas and adjoining slopes and plateaus represent a unique setting for addressing a number of theoretical issues about the biological aging process. This chapter presents information on aspects of growth, development, and aging in a Himalayan population residing in a high altitude, rugged environment in Nepal and discusses this information in the context of several theories about factors influencing biological aging.
This chapter reviews evidence that natural selection is acting or has acted on indigenous high-al... more This chapter reviews evidence that natural selection is acting or has acted on indigenous high-altitude populations of the Andean, Tibetan and East African plateaus and resulted in distinctive biological characteristics conferring vigor and health. It describes the results of classic era and genomic era approaches to detecting natural selection. Genomic era evidence of natural selection on high-altitude populations is accumulating rapidly and broadly supports that from the classic era. An important remaining step is to associate phenotypic with genomic variation and to associate them with survival and reproduction, the demographic currency of natural selection.
... the high-altitude native migrant to low altitude because of prior physiological adaptation to... more ... the high-altitude native migrant to low altitude because of prior physiological adaptation to high ... In a southern Peruvian coastal valley study location, three sub-populations were defined on the ... migrant status and altitude of place of birth: 1) low-altitude-born native non-migrants ...
The report describes height, weight and triceps skinfold measurement for 239 individuals from 5 t... more The report describes height, weight and triceps skinfold measurement for 239 individuals from 5 to 22 and 30 to 39 years of age living in the rural Tibetan village of Mugu, Nepal (altitude 3800m). It compares this population with a high-altitude Andean Quechua population and another high-altitude Tibetan population. A delay in height and weight is manifested by the Mugu population. Mugu children are shorter and lighter than the high-altitude Quechua sample during childhood and the early teens, yet they eventually achieve similar adult heights and weights. Mugu males are shorter and lighter than another Tibetan male sample. The reasons for the contrasting growth patterns are not known precisely due to present lack of thorough nutritional, epidemiological and genetical studies from Mugu.
Populations residing for millennia on the high-altitude plateaus of the world started natural exp... more Populations residing for millennia on the high-altitude plateaus of the world started natural experiments that we can evaluate to address questions about the processes of evolution and adaptation. A 2001 assessment in this journal summarized abundant evidence that Tibetan and Andean high-altitude natives had different phenotypes, and the article made a case for the hypothesis that different genetic bases underlie traits in the two populations. Since then, knowledge of the prehistory of high-altitude populations has grown, information about East African highlanders has become available, genomic science has grown exponentially, and the genetic and molecular bases of oxygen homeostasis have been clarified. Those scientific advances have transformed the study of high-altitude populations. The present review aims to summarize recent advances in understanding with an emphasis on the genetic bases of adaptive phenotypes, particularly hemoglobin concentration among Tibetan highlanders. EGLN1 and EPAS1 encode two crucial proteins contributing to oxygen homeostasis, the oxygen sensor PHD2 and the transcription factor subunit HIF-2α, respectively; they show signals of natural selection such as marked allele frequency differentiation between Tibetans and lowland populations. EPAS1 genotypes associated in several studies with the dampened hemoglobin phenotype that is characteristic of Tibetans at high altitude but did not associate with the dampened response among Amhara from Ethiopia or the vigorous elevation of hemoglobin concentration among Andean highlanders. Future work will likely develop understanding of the integrative biology leading from genotype to phenotype to population in all highland areas.
Women in a Tibetan speaking population living at 3250-3560 m in Upper Chumik, Nepal, have median ... more Women in a Tibetan speaking population living at 3250-3560 m in Upper Chumik, Nepal, have median ages at menopause and menarche of 46.8 and 16.2 years, respectively, assessed by the status quo technique. Recalled ages at menopause and menarche yield similar results and suggest a long-term existence of a pattern of relatively accelerated age at menopause and delayed age at menarche. Variation in the length of the calculated biological reproductive span in this sample is more strongly associated with recalled age at menopause than recalled age at menarche. The age at menopause in Upper Chumik is accelerated relative to that reported for Western industrial populations; however, these data do not permit drawing conclusions about the reasons underlying the acceleration.
... Cynthia M. Beall Department of Anthropology, Case Western Reserve University, Cleveland, OH 4... more ... Cynthia M. Beall Department of Anthropology, Case Western Reserve University, Cleveland, OH 441067125 USA ... Beall, CM, LA Almasy, J. Blangero, S. Williams-Blangero, GM Brittenham, KP Strohl, M. Decker, L. Vargas, M. Villena, R. Soria, A. Alarcon, and C. Gonzales. ...
▪ The high-altitude Andean and Tibetan Plateaus offer natural experimental settings for investi... more ▪ The high-altitude Andean and Tibetan Plateaus offer natural experimental settings for investigating the outcome of the past action of evolution and adaptation as well as those ongoing processes. Both Andean and Tibetan high-altitude natives are descended from sea-level ancestors; thus both initially encountered chronic, lifelong high-altitude hypoxia with the same homeostatic “toolbox” that evolved at sea level for responding to brief and transient hypoxia. Yet now they differ phenotypically in many traits thought to be important for offsetting chronic high-altitude hypoxia. Compared on the basis of mean values of five traits, the characteristics of Tibetan high-altitude natives differ more than those of Andean high-altitude natives from the ancestral or unselected response to chronic hypoxia exhibited by acclimatized lowlanders. This suggests that different evolutionary processes have occurred in the two geographically separate areas, although it is not clear why or how those processes differed. Answers to those questions require better knowledge of the prehistory of human populations on the plateaus, as well as information on new phenotypes and the relationship between phenotype and genotype.
The Himalayas and adjoining slopes and plateaus represent a unique setting for addressing a numbe... more The Himalayas and adjoining slopes and plateaus represent a unique setting for addressing a number of theoretical issues about the biological aging process. This chapter presents information on aspects of growth, development, and aging in a Himalayan population residing in a high altitude, rugged environment in Nepal and discusses this information in the context of several theories about factors influencing biological aging.
This chapter reviews evidence that natural selection is acting or has acted on indigenous high-al... more This chapter reviews evidence that natural selection is acting or has acted on indigenous high-altitude populations of the Andean, Tibetan and East African plateaus and resulted in distinctive biological characteristics conferring vigor and health. It describes the results of classic era and genomic era approaches to detecting natural selection. Genomic era evidence of natural selection on high-altitude populations is accumulating rapidly and broadly supports that from the classic era. An important remaining step is to associate phenotypic with genomic variation and to associate them with survival and reproduction, the demographic currency of natural selection.
... the high-altitude native migrant to low altitude because of prior physiological adaptation to... more ... the high-altitude native migrant to low altitude because of prior physiological adaptation to high ... In a southern Peruvian coastal valley study location, three sub-populations were defined on the ... migrant status and altitude of place of birth: 1) low-altitude-born native non-migrants ...
The report describes height, weight and triceps skinfold measurement for 239 individuals from 5 t... more The report describes height, weight and triceps skinfold measurement for 239 individuals from 5 to 22 and 30 to 39 years of age living in the rural Tibetan village of Mugu, Nepal (altitude 3800m). It compares this population with a high-altitude Andean Quechua population and another high-altitude Tibetan population. A delay in height and weight is manifested by the Mugu population. Mugu children are shorter and lighter than the high-altitude Quechua sample during childhood and the early teens, yet they eventually achieve similar adult heights and weights. Mugu males are shorter and lighter than another Tibetan male sample. The reasons for the contrasting growth patterns are not known precisely due to present lack of thorough nutritional, epidemiological and genetical studies from Mugu.
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