Biological and Physical Anthropology Commons^™

Does Market Integration Buffer Risk, Erode Traditional Sharing Practices And Increase Inequality? A Test Among Bolivian Forager-Farmers, Michael Gurven, Adrian V. Jaeggi, Christopher Von Rueden, Paul L. Hooper, Hillard Kaplan

ESI Publications

Sharing and exchange are common practices for minimizing food insecurity in rural populations. The advent of markets and monetization in egalitarian indigenous populations presents an alternative means of managing risk, with the potential impact of eroding traditional networks. We test whether market involvement buffers several types of risk and reduces traditional sharing behavior among Tsimane Amerindians of the Bolivian Amazon. Results vary based on type of market integration and scale of analysis (household vs. village), consistent with the notion that local culture and ecology shape risk management strategies. Greater wealth and income were unassociated with the reliance on others for …

Depression As Sickness Behavior? A Test Of The Host Defense Hypothesis In A High Pathogen Population, Jonathan Stieglitz, Benjamin C. Trumble, Melissa Emery Thompson, Aaron D. Blackwell, Hillard Kaplan, Michael Gurven

ESI Publications

Sadness is an emotion universally recognized across cultures, suggesting it plays an important functional role in regulating human behavior. Numerous adaptive explanations of persistent sadness interfering with daily functioning (hereafter “depression”) have been proposed, but most do not explain frequent bidirectional associations between depression and greater immune activation. Here we test several predictions of the host defense hypothesis, which posits that depression is part of a broader coordinated evolved response to infection or tissue injury (i.e. “sickness behavior”) that promotes energy conservation and reallocation to facilitate immune activation. In a high pathogen population of lean and relatively egalitarian Bolivian foragerhorticulturalists, …

Lambda Alpha Anthropology Honors Society (Lab): Bridging The Gap Between Coursework And Career, Adriana Stein, Stefanie Berganini

Student Research Symposium

Many anthropology majors gain an academic familiarity with the subject through coursework, but lack an understanding of how to utilize their anthropological skills outside of academia in future careers. To remedy this issue, the Lambda Alpha Beta Honor Society (LAB), a student-led anthropology organization at Portland State University, provides opportunities for participation in events that get students involved with our local community, such as non-profit organizations and local cultural institutions. Some of these organizations include the Oregon Museum of Science and Industry (OMSI), Clark Public Utilities, The Ridgefield Wildlife Refuge, Potluck in the Park, and Habitat for Humanity. As an …

Horses: How Saddle Style Defines A Culture And The Skeletal System, Brandy Morgan

Honors Theses

This paper examines the way in which various parameters affect injury type and prevalence in horse eventing. The human-horse relationship has a long history that has continued to evolve, and their relationship is still strong today, especially in the role of sports and entertainment. In equestrian sports, horseback riding has been found to be extremely dangerous in terms of prevalence and severity of injury. This paper evaluates how saddle style, the sex of the rider, rider experience, and nature of event impacts injury patterns specifically within horse eventing which utilizes an English styled saddle.

Horses: How Saddle Style Defines A Culture And The Skeletal System, Elizabeth Brandon

Honors Theses

Throughout history different cultures have been greatly impacted by horses and their uses. Today horseback riding is still a very popular sport, and though it is more dangerous than other forms of transportation, such as motorcycle riding, horseback riding is still used in entertainment, occupational, and leisure activities. Saddles have long been an important piece of equipment for riding. As the horse became a mode of transportation, many cultures had their own saddle style, but today there are two prominent saddle styles, the western and english styles. The western saddle style is used more for leisure, occupational, and rodeo riding. …

Inclusive Fitness And Differential Productivity Across The Life Course Determine Intergenerational Transfers In A Small-Scale Human Society, Paul L. Hooper, Michael Gurven, Jeffrey Winking, Hillard Kaplan

ESI Publications

Transfers of resources between generations are an essential element in current models of human life-history evolution accounting for prolonged development, extended lifespan and menopause. Integrating these models with Hamilton’s theory of inclusive fitness, we predict that the interaction of biological kinship with the age-schedule of resource production should be a key driver of intergenerational transfers. In the empirical case of Tsimane’ forager–horticulturalists in Bolivian Amazonia, we provide a detailed characterization of net transfers of food according to age, sex, kinship and the net need of donors and recipients. We show that parents, grandparents and siblings provide significant net downward transfers …

Ethics In The Field: Contemporary Challenges, Lisa C. Depaoli

Journal of Ecological Anthropology

No abstract provided.

Low Mineral Density Of A Weight-Bearing Bone Among Adult Women In A High Fertility Population, Jonathan Stieglitz, Bret Beheim, Benjamin C. Trumble, Felicia C. Madimenos, Hillard Kaplan, Michael Gurven

ESI Publications

Evolutionary theories of aging posit that greater reproductive effort causes somatic decline given a fundamental trade-off between investing energy in reproduction and repair. Few studies in high fertility human populations support this hypothesis, and problems of phenotypic correlation can obscure the expected trade-off between reproduction and somatic condition. This cross-sectional study investigates whether greater reproductive effort is associated with reduced calcaneal bone mineral density (BMD) among female Tsimane forager-farmers of lowland Bolivia. We also investigate whether female Tsimane BMD values are lower than sex- and age-matched US reference values, despite the fact that Tsimane engage in higher physical activity levels …

Leadership In An Egalitarian Society, Christopher Von Rueden, Michael Gurven, Hillard Kaplan, Jonathan Stieglitz

ESI Publications

Leadership is instrumental to resolution of collective action dilemmas, particularly in large, heterogeneous groups. Less is known about the characteristics or effectiveness of leadership in small-scale, homogeneous, and relatively egalitarian societies, in which humans have spent most of our existence. Among Tsimane’ forager-horticulturalists of Bolivia, we (1) assess traits of elected leaders under experimental and naturalistic conditions and (2) test whether leaders impact collective action outcomes. We find that elected leaders are physically strong and have more kin and other exchange partners. Their ranks on physical dominance, kin support, and trustworthiness predict how well their groups perform, but only where …

Political Influence Associates With Cortisol And Health Among Egalitarian Forager-Farmers, Christopher Von Rueden, Benjamin C. Trumble, Melissa Emery Thompson, Jonathan Stieglitz, Paul L. Hooper, Aaron D. Blackwell, Hillard Kaplan, Michael Gurven

ESI Publications

Background and objectives: Low social status increases risk of disease due, in part, to the psychosocial stress that accompanies feeling subordinate or poor. Previous studies report that chronic stress and chronically elevated cortisol can impair cardiovascular and immune function. We test whether lower status is more benign in small-scale, relatively egalitarian societies, where leaders lack coercive authority and there is minimal material wealth to contest.

Methodology: Among Tsimane’ forager-horticulturalists of lowland Bolivia, we compare informal political influence among men with urinary cortisol, immune activation (innate and acquired), and morbidity as assessed during routine medical exams.

Results: After …

Genomic Correlates Of Atherosclerosis In Ancient Humans, Albert Zink, L. Samuel Wann, Randall C. Thompson, Andreas Keller, Frank Maixner, Adel H. Allam, Caleb E. Finch, Bruno Frohlich, Hillard Kaplan, Guido P. Lombardi, M. Linda Sutherland, James D. Sutherland, Lucia Watson, Samantha L. Cox, Michael I. Miyamoto, Jagat Narula, Alexandre F. R. Stewart, Gregory S. Thomas, Johannes Krause

ESI Publications

Paleogenetics offers a unique opportunity to study human evolution, population dynamics, and disease evolution in situ. Although histologic and computed x-ray tomographic investigations of ancient mummies have clearly shown that atherosclerosis has been present in humans for more than 5,000 years, limited data are available on the presence of genetic predisposition for cardiovascular disease in ancient human populations. In a previous whole-genome study of the Tyrolean Iceman, a 5,300-year-old glacier mummy from the Alps, an increased risk for coronary heart disease was detected. The Iceman’s genome revealed several single nucleotide polymorphisms that are linked with cardiovascular disease in genome-wide association …

Funerary Artifacts, Social Status, And Atherosclerosis In Ancient Peruvian Mummy Bundles, M. Linda Sutherland, Samantha L. Cox, Guido P. Lombardi, Lucia Watson, Clide M. Valladolid, Caleb E. Finch, Albert Zink, Bruno Frohlich, Hillard Kaplan, David E. Michalik, Michael I. Miyamoto, Adel H. Allam, Randall C. Thompson, L. Samuel Wann, Jagat Narula, Gregory S. Thomas, James D. Sutherland

ESI Publications

Background: Evidence of atherosclerotic plaques in ancient populations has led to the reconsideration of risk factors for heart disease and of the common belief that it is a disease of modern times.

Methods: Fifty-one wrapped mummy bundles excavated from the sites of Huallamarca, Pedreros, and Rinconada La Molina from the Puruchuco Museum collection in Lima, Peru, were scanned using computed tomography to investigate the presence of atherosclerosis. Funerary artifacts contained within the undisturbed mummy bundles were analyzed as an attempt to infer the social status of the individuals to correlate social status with evidence of heart disease in …

Why Did Ancient People Have Atherosclerosis?: From Autopsies To Computed Tomography To Potential Causes, Gregory S. Thomas, L. Samuel Wann, Adel H. Allam, Randall C. Thompson, David E. Michalik, M. Linda Sutherland, James D. Sutherland, Guido P. Lombardi, Lucia Watson, Samantha L. Cox, Clide M. Valladolid, Gomaa Abd El-Maksoud, Muhammad Al-Tohamy Soliman, Ibrahem Badr, Abd El-Halim Nur El-Din, Emily M. Clarke, Ian G. Thomas, Michael I. Miyamoto, Hillard Kaplan, Bruno Frohlich, Jagat Narula, Alexandre F. R. Stewart, Albert Zink, Caleb E. Finch

ESI Publications

Computed tomographic findings of atherosclerosis in the ancient cultures of Egypt, Peru, the American Southwest and the Aleutian Islands challenge our understanding of the fundamental causes of atherosclerosis. Could these findings be true? Is so, what traditional risk factors might be present in these cultures that could explain this apparent paradox? The recent computed tomographic findings are consistent with multiple autopsy studies dating as far back as 1852 that demonstrate calcific atherosclerosis in ancient Egyptians and Peruvians. A nontraditional cause of atherosclerosis that could explain this burden of atherosclerosis is the microbial and parasitic inflammatory burden likely to be present …

Atherosclerosis: A Longue Durée Approach, L. Samuel Wann, Randall C. Thompson, Adel H. Allam, Caleb E. Finch, Albert Zink, Hillard Kaplan, Bruno Frohlich, Guido P. Lombardi, M. Linda Sutherland, James D. Sutherland, Lucia Watson, Samantha L. Cox, Michael I. Miyamoto, Alexandre F. R. Stewart, Jagat Narula, Gregory S. Thomas

ESI Publications

Fernand Braudel popularized the longue durée approach to scholarly investigation in the mid-20th century. The longue durée approach can be loosely translated to mean “look for the big picture, synthesize data collected using all available methodology over the long periods of time to identify fundamental principles, rather than becoming preoccupied with isolated observations.” Braudel, a historian and economist, emphasized observation of enduring historical structures and analysis of long-term, panoramic economic trends rather than concentrating on detailed descriptions of particular events or individuals. He also urged the use of insight gained from many scholarly disciplines to identify the essential underpinnings of …

From Sydney To Syracuse A Transcontinental Exploration Of Women’S Health In Karen Refugee Communities, Darcy Cherlin

Renée Crown University Honors Thesis Projects - All

From Sydney to Syracuse a Transcontinental Exploration of Women’s Health in Karen Refugee Communities. There are many impediments to refugee women’s access to health care and sexual and reproductive services in their countries of resettlement, including language difference, transportation, and absence of culturally appropriate support. Through focus groups and participatory observation this paper identifies some major challenges that Karen (an ethnic group from Burma) women face accessing health care in their respective cities of resettlement (Syracuse, New York or Sydney, Australia). It is through such documentation and analysis that policies and services can be improved and any harm they …

The Evolutionary Fitness Of Personality Traits In A Small-Scale Subsistence Society, Michael Gurven, Christopher Von Rueden, Jonathan Stieglitz, Hillard Kaplan, Daniel Eid Rodriguez

ESI Publications

"Personality, or “behavioral syndromes”, are relatively stable dispositional traits and behaviors that have now been identified in a myriad of social species (Gosling, 2001; Sih et al., 2004), and with clear consequences on fitness (Smith & Blumstein, 2008). The canalization of personality during development and relative stability thereafter, despite varying circumstances over the life course that might otherwise favor greater plasticity, is an important problem attracting much theoretical and empirical attention (Dall et al., 2004; Dingemanse et al., 2010). Further, personality is highly heritable, yet how heritable genetic variation in personality traits is maintained over generations remains another conundrum (Buss …

Dynamical Structure Of A Traditional Amazonian Social Network, Paul L. Hooper, Simon Dedeo, Ann E. Caldwell Hooper, Michael Gurven, Hillard Kaplan

ESI Publications

Reciprocity is a vital feature of social networks, but relatively little is known about its temporal structure or the mechanisms underlying its persistence in real world behavior. In pursuit of these two questions, we study the stationary and dynamical signals of reciprocity in a network of manioc beer (Spanish: chicha; Tsimane’: shocdye’) drinking events in a Tsimane’ village in lowland Bolivia. At the stationary level, our analysis reveals that social exchange within the community is heterogeneously patterned according to kinship and spatial proximity. A positive relationship between the frequencies at which two families host each other, controlling for kinship and …

Patterns Of Senescence In Human Cardiovascular Fitness: Vo2 Max In Subsistence And Industrialized Populations, Anne C. Pisor, Michael Gurven, Aaron D. Blackwell, Hillard Kaplan, Gandhi Yetish

ESI Publications

Objectives—This study explores whether cardiovascular fitness levels and senescent decline are similar in the Tsimane of Bolivia and Canadians, as well as other subsistence and industrialized populations. Among Tsimane, we examine whether morbidity predicts lower levels and faster decline of cardiovascular fitness, or whether their lifestyle (e.g., high physical activity) promotes high levels and slow decline. Alternatively, high activity levels and morbidity might counterbalance such that Tsimane fitness levels and decline are similar to those in industrialized populations.

Methods—Maximal oxygen uptake (VO2max) was estimated using a step test heart rate method for 701 participants. We compared these estimates …

Age-Independent Increases In Male Salivary Testosterone During Horticultural Activity Among Tsimane Forager-Farmers, Benjamin C. Trumble, Daniel K. Cummings, Kathleen A. O'Connor, Darryl J. Holman, Eric A. Smith, Hillard Kaplan, Michael D. Gurven

ESI Publications

Testosterone plays an important role in mediating male reproductive trade-offs in many vertebrate species, augmenting muscle and influencing behavior necessary for male-male competition and mating-effort. Among humans, testosterone may also play a key role in facilitating male provisioning of offspring as muscular and neuromuscular performance are deeply influenced by acute changes in testosterone. This study examines acute changes in salivary testosterone among 63 Tsimane men ranging in age from 16–80 (mean 38.2) years during one-hour bouts of treechopping while clearing horticultural plots. The Tsimane forager-horticulturalists living in the Bolivian Amazon experience high energy expenditure associated with food production, have high …

Household Task Delegation Among High-Fertility Forager-Horticulturalists Of Lowland Bolivia, Jonathan Stieglitz, Michael Gurven, Hillard Kaplan, Paul L. Hooper

ESI Publications

Human kin cooperation is universal, leading researchers to label humans as “cooperative breeders.” Despite widespread interest in human cooperation, there has been no systematic study of how household economic decision making occurs. We document age and sex profiles of task delegation by parents to children ages 4–18 among Bolivian forager-horticulturalists. We test for sex differences in the probability of delegation and examine whether tasks are more likely delegated as household labor demand increases. We also test whether food acquisition tasks are more likely delegated to higher producers.We find mixed support for the prediction that girls are more likely delegated domestic …

Physical Activity And Modernization Among Bolivian Amerindians, Michael Gurven, Adrian V. Jaeggi, Hillard Kaplan, Daniel Cummings

ESI Publications

Background: Physical inactivity is a growing public health problem, and the fourth leading risk factor for global mortality. Conversely, indigenous populations living traditional lifestyles reportedly engage in vigorous daily activity that is protective against non-communicable diseases. Here we analyze physical activity patterns among the Tsimane, forager-horticulturalists of Amazonian Bolivia with minimal heart disease and diabetes. We assess age patterns of adult activity among men and women, test whether modernization affects activity levels, and examine whether nascent obesity is associated with reduced activity.

Methods and Findings: A factorial method based on a large sample of behavioral observations was employed …

How Universal Is The Big Five? Testing The Five-Factor Model Of Personality Variation Among Forager-Farmers In The Bolivian Amazon, Michael Gurven, Christopher Von Rueden, Maxim Massenkoff, Hillard Kaplan, Marino Lero Vie

ESI Publications

The five-factor model (FFM) of personality variation has been replicated across a range of human societies, suggesting the FFM is a human universal. However, most studies of the FFM have been restricted to literate, urban populations, which are uncharacteristic of the majority of human evolutionary history. We present the first test of the FFM in a largely illiterate, indigenous society. Tsimane forager–horticulturalist men and women of Bolivia (n = 632) completed a translation of the 44-item Big Five Inventory (Benet-Martínez & John, 1998), a widely used metric of the FFM. We failed to find robust support for the FFM, based …

Modernization, Sexual Risk-Taking, And Gynecological Morbidity Among Bolivian Forager-Horticulturalists, Jonathan Stieglitz, Aaron D. Blackwell, Raúl Quispe Gutierrez, Edhitt Cortez Linares, Michael Gurven, Hillard Kaplan

ESI Publications

Sexual risk-taking and reproductive morbidity are common among rapidly modernizing populations with little material wealth, limited schooling, minimal access to modern contraception and healthcare, and gendered inequalities in resource access that limit female autonomy in cohabiting relationships. Few studies have examined how modernization influences sexual risk-taking and reproductive health early in demographic transition. Tsimane are a natural fertility population of Bolivian forager-farmers; they are not urbanized, reside in small-scale villages, and lack public health infrastructure. We test whether modernization is associated with greater sexual risk-taking, report prevalence of gynecological morbidity (GM), and test whether modernization, sexual risk-taking and parity are …

Choosing The Best Plant For The Job: A Cost-Effective Assay To Prescreen Ancient Plant Remains Destined For Shotgun Sequencing, Nathan Wales, J. Alberto Romero-Navarro, Enrico Cappellini, M. Thomas P. Gilbert

Anthropology Articles

DNA extracted from ancient plant remains almost always contains a mixture of endogenous (that is, derived from the plant) and exogenous (derived from other sources) DNA. The exogenous ‘contaminant’ DNA, chiefly derived from microorganisms, presents significant problems for shotgun sequencing. In some samples, more than 90% of the recovered sequences are exogenous, providing limited data relevant to the sample. However, other samples have far less contamination and subsequently yield much more useful data via shotgun sequencing. Given the investment required for high-throughput sequencing, whenever multiple samples are available, it is most economical to sequence the least contaminated sample. We present …

Why Do Women Have More Children Than They Want? Understanding Differences In Women's Ideal And Actual Family Size In A Natural Fertility Population, Lisa Mcallister, Michael Gurven, Hillard Kaplan, Jonathan Stieglitz

ESI Publications

Objectives—We develop and test a conceptual model of factors influencing women’s ideal family size (IFS) in a natural fertility population, the Tsimane of Bolivia. The model posits affects of socioecology, reproductive history, maternal condition, and men’s IFS. We test three hypotheses for why women may exceed their IFS despite experiencing socioeconomic development: (H1) limited autonomy; (H2) improved maternal condition; and (H3) low returns on investments in embodied capital.

Methods—Women’s reproductive histories and prospective fertility data were collected from 2002 to 2008 (n = 305 women). Semistructured interviews were conducted with Tsimane women to study the perceived value of …

Eating Behaviors And Body Composition Among College Freshmen: The Effect Of Dietary And Commensal Culture On Biological Outcomes, Amelia E. Sancilio

Lawrence University Honors Projects

As new college students become autonomous eaters, they may independently develop behaviors related to food that fulfill both biological and cultural purposes. I report here on the results of a biocultural, mixed-methods study of 21 students’ first term of college residence. Interview data and anthropometric measurements permit exploration of the interaction between a shift in participants’ cultural surroundings, physical condition, and food-related thoughts and actions. Participants’ goals of fulfilling their student responsibilities and maintaining social relationships predominantly dictated when, where, and what they ate, while their level of satisfaction with these behaviors was associated with whether their actions were consistent …

Fatty Acid Composition In The Mature Milk Of Bolivian Forager-Horticulturalists: Controlled Comparisons With A Us Sample, Melanie A. Martin, William D. Lassek, Steven J. C. Gaulin, Rhobert W. Evans, Sheela S. Geraghty, Barbara S. Davidson, Ardythe L. Morrow, Hillard Kaplan, Michael Gurven

ESI Publications

Breast milk fatty acid (FA) composition varies greatly among individual women, including in percentages of the long-chain polyunsaturated FAs (LCPUFA) 20:4n-6 (arachidonic acid, AA) and 22:6n-3 (docosahexaenoic acid, DHA), which are important for infant neurological development. It has been suggested that owing to wide variation in milk LCPUFA and low DHA in Western diets, standards of milk FA composition should be derived from populations consuming traditional diets. We collected breast milk samples from Tsimane women at varying lactational stages (6–82 weeks). The Tsimane are an indigenous, natural fertility, subsistence-level population living in Amazonia Bolivia. Tsimane samples were matched by lactational …

From The Womb To The Tomb: The Role Of Transfers In Shaping The Evolved Human Life History, Michael Gurven, Jonathan Stieglitz, Paul L. Hooper, Cristina Gomes, Hillard Kaplan

ESI Publications

Humans are the longest living and slowest growing of all primates. Although most primates are social, humans are highly cooperative and social in ways that likely co-evolved with the slow human life history. In this paper we highlight the role of resource transfers and non-material assistance within and across generations in shaping low human mortality rates. The use of complex cooperative strategies to minimize risk is a necessary precursor for selecting further reductions in mortality rate in late adulthood. In conjunction with changes in the age-profile of production, the impacts of resource transfers and other forms of cooperation on reducing …

Implications Of Land Development On Nomadic Pastoralism: Ecological Relaxation And Biosocial Diversity In Human Populations, Hannah R. Bradley

Scripps Senior Theses

Nomadic pastoralism is an ancient subsistence strategy, historically balanced and in continuity with sedentary societies. Sedentarization of nomads occurs normally because of ecological disasters, economic opportunities, urbanization, and government policy. In this paper, I examine the effect of changing land use patterns on nomadic pastoral populations in Asia, Africa, and the Middle East, using biogeographic methodology to further explore the contemporary relationship between humans and their environments. Nomadic population information gleaned from diverse ethnographic studies, and GIS data on anthropogenic biome distributions, were used to calculate changes in nomadic population, area of developed land, and nomadic/sedentary population density over the …

Infidelity, Jealousy, And Wife Abuse Among Tsimane Forager-Farmers: Testing Evolutionary Hypotheses Of Marital Conflict, Jonathan Stieglitz, Michael Gurven, Hillard Kaplan, Jeffrey Winking

ESI Publications

What causes marital conflict, and which marital conflicts are more likely to result in men’s violence against their wives? It has long been argued that men’s jealousy over women’s infidelity is the strongest impetus to men’s lethal and non-lethal violence against female partners. Less is known about the extent to which women’s jealousy over men’s infidelity precipitates men’s violence against female partners. Husbands are more likely than wives to commit infidelity, and men and women report a similar frequency and intensity of jealous emotions during recalls of potential infidelity. If men are likely to use time and resources for pursuit …