Shirley, Meghan, U. College London, London, UK - To aid research on 'Body Composition and the Brain: Investigating Life History Trade-offs in Living Humans,' supervised by Dr. Jonathan Wells
Preliminary abstract: Energy resources in any given environment are finite. Life history theory examines trade-offs between competing functions such as maintenance and reproduction across an organism's life course. For early humans, the evolution of a metabolically expensive brain was likely associated with reorganized energy investment and/or alterations in life history strategy and behavior. Insight into how the human brain was afforded may be most readily achieved with attention directed to investment 'decisions' at the level of organs and tissues. For example, Aiello and Wheeler's (1995) 'expensive tissue' hypothesis proposed that a reduction in the size of the human gut enabled encephalization. Research has demonstrated tissue trade-offs in a range of animals, yet empirical studies of human investment strategies remain rare. With the collection of MRI and body composition data from healthy adults, this project will investigate trade-offs between the human brain and other 'expensive' tissues of the body, trade-offs between the brain and adipose tissue, and also positive brain-body phenotype associations. Further, the study will examine the effect of early life experience on phenotype. This data will add to knowledge of the variability with which modern humans 'strategically' manage energy investment and lead to more robust inferences concerning hominin life history evolution.
DeCaro, Dr. Jason A., U. of Alabama, Tuscaloosa, AL - To aid research on 'Physical Activity and the Architecture of Daily Life among Alabama Mexican Americans: A Biocultural Investigation'
DR. JASON A. DeCARO, University of Alabama, Tuscaloosa, Alabama, was awarded funding in October 2007 to aid research on 'Physical Activity and the Architecture of Daily Life among Alabama Mexican Americans: A Biocultural Investigation.' Rising global obesity rates, and the historically limited effectiveness of behavioral interventions in addressing them, motivate the search for new understandings of biocultural and psychosocial determinants of physical activity. Physical activity occurs as a constituent of broader daily routines that are culturally constructed, complexly motivated, and socially constrained. Hence, daily routines may be viewed as a mechanism through which culture is progressively embodied across the life course, with body size and composition among the outcomes. In West Alabama, interviews, detailed daily activity diaries, 24-hour 5-day actigraphy (accelerometry), and BMI/body composition measurements were undertaken with 37 Mexican/Mexican-American young adults, including both recent non-student immigrants and college students. High agreement across subgroups regarding ideals for leisure-time physical activity intersect with profound intergroup and gender variation in beliefs and practices regarding the integration of physical activity into daily life. Further, the social context of physical activity moderates its relation to body size and composition. By combining biological, cultural, and behavioral data, it is possible to open new windows into embodiment as a biocultural process.
Hodges-Simeon, Carolyn Randolph, U. of California, Santa Barbara, CA - To aid research on 'Life History Trade-offs Affecting the Development of Human Sexual Dimorphism,' supervised by Dr. Steven J. Gaulin
CAROLYN R. HODGES-SIMEON, then a student at University of California, Santa Barbara, California, was awarded a grant in October 2010 to aid research on 'Life History Trade-Offs Affecting the Development of Human Sexual Dimorphism,' supervised by Dr. Steven J. Gaulin. The human vocal voice is sexually dimorphic in two primary ways: males have lower 'fundamental frequency' (F0, the perceptual correlate of which is 'pitch') and more closely spaced 'formant position' (Pf; also termed 'resonance'). These characteristics exhibit a pronounced and abrupt change during adolescence, marking the advancement of puberty. Research and data gathering target the developmental associations between dimorphic vocal characteristics (F0 and Pf), testosterone, immune functioning (secretory IgA and CRP), and energetic status (BMI and height) in adolescent boys in a non-industrialized population: the Tsimane' of lowland Bolivia. In doing so, this project uses the ontogeny of male vocal characteristics as a model system for examining two major theories in human evolutionary biology: 1) Life history theory (by examining trade-offs between reproductive and somatic investment); and 2) Immunocompetence handicap theory of sexual selection (by investigating whether sexually dimorphic signals are honest indicators of immunocompetence). Results indicate that males in better condition -- with better energetic and immune investment -- have higher testosterone levels, which are associated with lower voices. This research presents the first evidence that male vocal features are linked with condition, and that this association is mediated by testosterone.
McCabe, Collin Michael, Harvard U., Cambridge, MA - To aid research on 'Unwelcome Guests: Human-rodent Cohabitation and its Implications for Disease Transfer in Sedentary Agricultural Populations,' supervised by Dr. Richard Wrangham
Preliminary abstract: Rodents have inhabited human settlements since at least the advent of agriculture and sedentary lifestyles. This close contact between humans and rodents has been, and still is, a source of many emerging zoonotic diseases. However, little is known about what drives species to commensal lifestyles, and even less is known about whether these commensal species are more likely than non-commensal rodents to carry novel zoonotic pathogens. The aim of this study is to investigate certain behavioral and ecological factors that favor commensal living and pathogen burdens in East African rodents. I hypothesize that more exploratory rodent species with broader diets will more likely be commensal, and will likely have higher pathogen burdens. I plan to live-trap rodents in central Kenya from a community of 25 wild species, in both recently settled human agricultural villages and adjacent, undisturbed habitats to determine each species' level of commensality and the features of these wild rodents that favor commensal living. I will also obtain biological samples from these rodents to determine the zoonotic pathogen burdens. By enriching knowledge of rodent disease ecology, this project will provide data to hone or even transform our understanding of selective pressures of zoonotic pathogens on early agriculturalists.
Leidy Sievert, Dr. Lynnette, U. of Massachusetts, Amherst, MA - To aid research on 'Do Women Who Think They Know Really Know? Validating Signals of Ovulation'
DR. LYNNETTE LEIDY SIEVERT, of the University of Massachusetts in Amherst, Massachusetts, received funding in November 2002 to aid research on signals of ovulation in women who believe they know when they ovulate. Sievert tested whether or not women who think they know when they ovulate really do know, by assessing the concordance between perceived signals of ovulation and an elevated level of urinary LH, a biological indicator of ovulation. Participants were ages 18 to 46, had regular menstrual periods, were using no form of hormonal contraception, and believed they knew when they ovulated. Fifty-three women began the study. Signals of ovulation reported at initial interview included cervical discharge (68%), abdominal pain (64%), increased libido (30%), changes in mood or energy (25%), basal body temperature (17%), and other, infrequently reported symptoms (45%). Signal reporting varied in relation to smoking habits, body mass index, and health status. Thirty-six women provided a total of 87 urine specimens for LH testing. Thirty-seven of the specimens tested positive for an LH surge, for a concordance rate of 43%. Using the first tested cycle from the 36 women who provided urine specimens, 13 demonstrated an LH surge, for a concordance rate of 36%. The mean level of accuracy among the 15 women who contributed three to six urine specimens was 49%. It appeared, then, that between one-third and one-half of women who thought they knew when they ovulated were correct.
Downey, Dr. Greg, Macquarie U., Ryde, Australia - To aid research and writing on 'Homo Athleticus: Comparative Sports and Human Physiological Diversity' - Richard Carley Hunt Fellowship
DR. GREG DOWNEY, Macquarie University, Sydney, Australia, was awarded a Hunt Postdoctoral Fellowship in 2006 to aid research and writing on 'The Athletic Animal: Sports and Human Potential.' The book uses a wide range of research on athletes from across many cultures - from Kenyan runners and Korean pearl divers, to no-holds-barred fighters in Brazil and Korean archers - to highlight how humans drive their own physiological and neurological development into distinctive configurations through training regimens, especially running, climbing, throwing, fighting, hitting, and other sports-related activities. Although athletes are extreme examples, they illustrate clearly how culture, patterns of behaviour, training, and body ideals have tangible effects on our bodies and brains. Based in dynamic systems theory and reappraisals of phenotypic plasticity, the book attempts to demonstrate a problem-driven synthesis of findings from both biological and cultural anthropology. Growing out of the research related to this book were also several articles, including one that explored how coaching in the Afro-Brazilian martial art and dance, capoeira, facilitates novices' acquisition of their own idiosyncratic movement techniques, and another on the relation of the 'mirror neuron' system in the human brain to imitative learning in skill acquisition.
Downey, Greg. 2008. Scaffolding Imitation in Capoeira: Physical Education and Enculturation in an Afro-Brazilian Art. American Anthropologist 110(2):204-213
Downey, Greg. 2010. 'Practice without Theory': A Neuroanthropological Perspective on Embodied Learning. Journal of the Royal Anthropological Institute (N.S.):S22-S40.
Hoke, Morgan Kathleen, Northwestern U., Evanston, IL - To aid research on 'Changing Economic Activity, Infant Feeding, and Early Growth among the Quechua of Nuñoa, Peru,' supervised by Dr. William Leonard
Preliminary abstract: This biocultural research project examines the changing practices of infant feeding and the emergence of early growth inequalities in Nuñoa, Peru in light of ongoing political and economic changes, specifically the emergence of a new dairy industry and an increasing reliance on wage labor. Infancy is a critical period in which environmental and social inputs can have a significant effect on both health and socioeconomic outcomes later in life. Early nutrition has been shown to be particularly important. Drawing on anthropological and health literature on infant feeding, scholarship on the developmental origins of health and disease, and biocultural anthropology to inform research questions, this study represents a work of 'ethnographic human biology' (Wiley 2004). Previous anthropological research in Nuñoa dating to the 1960's allows findings to be contextualized within the political-economic and biological history of the region. Research methods include both ethnographic and biological approaches such as participant observation, interviews, infant nutritional assessment, anthropometric measurements, and infant focal follows. Original data will be analyzed to compare infant nutrition and growth between contemporary communities participating in different economic activities. Additional comparisons will be made with data collected in previous waves of research to identify dietary changes and highlight key changes in the growth process in the face of fifty years of economic changes.
Melby, Dr. Melissa Kathleen, National Institute of Health and Nutrition, Tokyo, Japan - To aid research on 'Developmental Origins of Metabolic Syndrome: Study Utilizing the Japanese Maternal and Child Health Handbook'
DR. MELISSA K. MELBY, National Institute of Health and Nutrition, Tokyo, Japan was awarded a grant in October 2008 to aid research on 'Developmental Origins of Metabolic Syndrome: Study Utilizing the Japanese Maternal and Child Health Handbook.' The 'Developmental Origins of Health and Disease' hypothesis posits that in utero stress such as nutritional restriction resulting in low birth weight (LBW) increases later life risk of metabolic-syndrome related disease. Understanding risk factors for LBW thus has implications for later life health. Among singleton full-term births (N~437) in Japan, females were three times more likely to be born at LBW than males. For males, gestational length was the biggest predictor of LBW, but gestational length was not a significant predictor of female LBW. Instead maternal weight at first prenatal exam, and total gestational weight gain after that exam, were most predictive. For girls only, primiparity and maternal history of LBW babies also increased risk, while maternal height decreased risk. If given adequate time in the womb, male babies appear largely immune to early pre-natal or pre-conception maternal condition and low maternal gestational weight gain. Female babies appear to be very sensitive to maternal condition, particularly early/initial weight and weight gain, as well as reproductive history. BMI at age 6-7 appears independent of birth weight and maternal gestational weight gain for boys, while girls' age 6-7 BMI appears more dependent on reproductive history, gestational weight gain, and resulting birth weight.
Snodgrass, James J., Northwestern U., Evanston, IL - To aid research on 'Energetics, Health, and Lifestyles Change among the Yakut of Siberia,' supervised by Dr. William R. Leonard
JAMES J. SNODGRASS, Northwestern University, Evanston, Illinois, received funding in May 2002 to aid research on 'Energetics, Health, and Lifestyles Change among the Yakut of Siberia,' supervised by Dr. William R. Leonard. This study examined the health consequences of economic modernization in the Yakut (Sakha), a high-latitude indigenous population of horse and cow pastoralists from the Sakha Republic of Russia. The two main research objectives were: 1) to investigate metabolic adaptation; and 2) to explore health and energy balance within the context of economic modernization. All research was conducted in the rural Siberian village of Berdygestiakh, Russia. Data were collected on: basal metabolic rate (BMR), total energy expenditure (TEE), blood pressure, body composition, diet, thyroid hormones, Epstein-Barr virus antibodies, and lifestyle and socioeconomic status. The results of this study indicate that, regardless of which reference standard is used, Yakut men and women have elevated BMRs. This study did not document any significant relationships between lifestyle measures and BMR, which suggests that genetic factors play an important role in metabolic elevation. This research provides baseline information on health and energy balance in the Yakut and investigates how specific lifestyle (e.g., physical activity and diet) and socioeconomic (e.g., income and education) factors contribute to the development of obesity and hypertension. Relatively low levels of physical activity, documented using the doubly labeled water technique, play an important role in the development of obesity in the Yakut, especially among women. Obesity and hypertension are emerging health issues among the Yakut. Affluence is associated with obesity among men, but not women; this parallels findings from nationally representative studies in Russia that document that health changes are more closely tied to socioeconomic status in men than women.
Snodgrass, J. Josh, William R. Leonard, M.V. Sorensen, L.A. Tarskaia, and M.J. Mosher. 2008. The Influence of Basal Metabolic Rate on Blood Pressure among Indigenous Siberians. American Journal of Physical Anthropology 137(2):145-155
Snodgrass, J.J., M.V. Sorensen, L.A. Tarskaia, and W.R. Leonard. 2007. Adaptive Dimensions of Health Research among Indigenous Siberians. American Journal of Human Biology 19:165-180.
Snodgrass, J.J., W.R. Leonard, L.A. Tarskaia, T.W. McDade, et al. 2007. Anthropometric Correlates of C-Reactive Protein among Indigenous Siberians. Journal of Physiological Anthropology 26:241-246.
Snodgrass, J. Josh, et al. 2006. The Emergence of Obesity among Indigenous Siberians. Journal of Physiological Anthropology 25(1):75-84.
Snodgrass, J. Josh, et al. 2006. Total Energy Expenditure in the Yakut (Sakha) of Siberia as Measured by the Doubly Labeled Water Method. American Journal of Clinical Nutrition 84:798-806.
Snodgrass, J. Josh, W.R. Leonard, L. Tarskaia, V.P. Alekseev, and V.G. Krivoshapkin. 2005. Basal Metabolic Rate in the Yakut (Sakha) of Siberia. American Journal of Human Biology 17:155-172.
Dufour, Dr. Darna L., U. of Colorado, Boulder, CO - To aid research on 'Work Efficiency in Lactating Women'
DR. DARNA L. DUFOUR, University of Colorado, Boulder, Colorado, was awarded a grant in July 2004 to aid research on 'Work Efficiency in Lactating Women.' Lactation is the most costly phase of reproduction for human females and can increase a women's energy needs by 30 percent. Women can potentially meet this increase in energy needs by increasing their food energy intake, decreasing their physical activity and/or utilizing their body fat stores. This study examined a fourth way women can potentially meet their increased energy needs in lactation, that is by an increase in work (metabolic) efficiency in exercise. A sample of exclusively breastfeeding women was recruited and their work efficiency in exercise measured at peak lactation (3-4 months postpartum) and then again after weaning. Work efficiency in exercise was measured as delta efficiency (the ratio of work accomplished to energy needed to accomplish that work) using a submaximal exercise test on a cycle ergometer. The results demonstrated that delta efficiency is significantly higher at peak lactation than after weaning. Further, delta efficiency at peak lactation was significantly higher than in a control sample of non-pregnant, non-lactating women. These findings suggest that in addition to increased food energy intake, decreased physical activity and the utilization of fat stores, women can compensate for the extra energy demands of lactation through increases in work efficiency.