Martin, Melanie Ann, U. of California, Santa Barbara, CA - To aid research on 'Maternal Factors Influencing Variation in Infant Feeding Practices in a Natural Fertility Population,' supervised by Dr. Michael Gurven
MELANIE A. MARTIN, then a student at University of California, Santa Barbara, California, was awarded funding in April 2012 to aid research on 'Maternal Factors Influencing Variation in Infant Feeding Practices in a Natural Fertility Population,' supervised by Dr. Michael Gurven. Exclusive breastfeeding for six months and continued breastfeeding for two years or longer promote optimal infant health and growth. Globally, however, many mothers introduce complementary foods and wean earlier than recommended. This study examined factors associated with variation in infant feeding practices in an indigenous population, the Tsimane of Bolivia. During 2012-2013, interviews and anthropometric measurements were collected from 147 Tsimane mothers and infants aged 0-36 months, with 47 mother-infant pairs visited repeatedly over eight months. Half of Tsimane infants were introduced to complementary foods by four months of age, although 75 percent were still breastfed at two years. On average, male infants were exclusively breastfed longer and weaned later than females. No other maternal, infant, or household factors measured influenced the duration of exclusive breastfeeding duration. Age at weaning, however, was increased by the number of family members over the age of 10, and decreased by a mother's subsequent pregnancy and total number of living offspring. Poor growth was evident in only two percent of infants aged 0-6 months, but increased markedly after twelve months. Earlier weaning and/or the quantity or quality of complementary foods may more significantly impact Tsimane infant growth and health outcomes than does early complementary feeding.
Rowe, Elizabeth Jane, Temple U., Philadelphia, PA - To aid research on 'The Role of the Progesterone Receptor in the Menstrual Cycle,' supervised by Dr. L. Christie Rockwell
ELIZABETH JANE ROWE, then a student at Temple University, Philadelphia, Pennsylvania, was awarded a grant in May 2008, to aid research on 'The Role of the Progesterone Receptor in the Menstrual Cycle,' supervised by Dr. L. Christie Rockwell. Much of the work in Physical Anthropology related to variation in women's reproductive function has been heavily focused on evolutionary models to explain the responsiveness of ovarian steroid production to ecological conditions. Underlying functionally significant, genetic variation that also likely impacts reproductive phenotypes has seldom been investigated. This project addressed this problem by investigating the impact of a common, functionally significant variant of the progesterone receptor gene on uterine function and the menstrual cycle among women in the Philadelphia area. Women who carried the variant differed from women who did not with regard to menstrual cycle characteristics. Furthermore, the variant was found to modify the impact of life history and ecological variables on both uterine function and the menstrual cycle. These findings indicate that genetic variation should be considered in future models for women's reproduction in Physical Anthropology. Additionally, uterine function and menstrual cycle characteristics did not reflect ovarian hormone levels, but instead were significantly predicted by ecological variables that indicated energetic status. These findings, coupled with results of other work, indicate that the uterus responds directly to environmental cues, and therefore suggest that it plays an active role in the maternal decision to commit resources to gestation.
DeCaro, Jason A., Emory U., Atlanta, GA - To aid research on 'The Social Ecology of Childhood Stress: Reactivity and Family Function in North Central Georgia, U.S.A.' supervised by Dr. Carol M. Worthman
JASON A. DECARO, while a student at Emory University in Atlanta, Georgia, was awarded a grant in November 2001 to aid research on the social ecology of childhood stress in north-central Georgia, U.S.A., under the supervision of Dr. Carol M. Worthman. DeCaro's research was designed to evaluate whether children's reactivity (physiological response to stress or arousal) during the transition from preschool to kindergarten was related to their parents' economic security; whether the 'routinization' of family life and stability in the social ecology of the home predicted children's reactivity during this transition; and whether the stability of children's social environment and their reactivity predicted functional outcomes. Ethnographic interviews with parents in forty-five metropolitan Atlanta families focused on work, finances, economic security, time management, and school and neighborhood choices and satisfaction. Prior to and following the transition into kindergarten, DeCaro collected saliva samples from children and parents three times a day for seven days, in order to test for levels of cortisol, a hormone of physiologic arousal. He also monitored children's heart rates during a puppet-based psychobehavioral interview. Parents were asked to track on hand computers their and their children moods, contexts, and experiences for seven days. Questionnaires covered children's behavioral and somatic symptomatology and preschool educational outcomes. Preliminary analysis suggested that cardiovascular response during a mild social challenge predicted the density of parents' schedules but that mothers' and fathers' types of 'busyness' had different effects on household ecology and on children's responses to experience. The study was expected to provide insights into the cultural construction of the 'work' of the family, which profoundly affects both the actual form and the perception of family life by family members and thus what precisely is 'stressful' about it.
DeCaro, Jason A. and Carol M. Worthman. 2006 Cultural Models, Parent Behavior, and Young Child Experience in Working American Families. Parenting: Science and Practice 7(2): 177-203.
Masterson, Erin Elizabeth, U. of Washington, Seattle, WA - To aid research on 'Putting Teeth into the Developmental Origins Hypothesis: Early Childhood Ecology, Enamel Defects and Adolescent Growth,' supervised by Dr. Daniel Eisenberg
Preliminary abstract: Like a window into the past, adult teeth may reflect early childhood ecology. Dental enamel on the permanent maxillary incisors calcifies incrementally during early childhood (0-5 years of age), is highly-sensitive to biological stress, and doesn't repair over the life course. Developmental defects in the enamel (DDE) are caused by metabolic disruption during development, including micronutrient deficiency, gastrointestinal disturbance, and bacterial and viral infections. According to developmental origins of health and disease (DOHaD) research findings and evolutionary theory, these factors may also influence chronic disease risk later in life. Bioarcheological findings have indicated an association exists between DDEs in the permanent dentition and increased morbidity and early mortality among skeletal remains, suggesting that dental enamel may be a retrospective marker of early childhood ecology. However, the association between DDEs and long-term health consequences has never been tested in a contemporary population. The purpose of the proposed project is to assess whether DDEs -- developed during the first five years of life -- is a marker of early childhood ecology and predictor of adolescent growth in a contemporary population. Based on evolutionary theory, we hypothesize that enamel defects mark a physiologically-stressful early childhood that predicts unhealthy growth in adolescence. We expect our study to provide the scientific community more confidence in interpretations of DDEs, and to introduce a new measure of early childhood ecology that may enable widespread study of the DOHaD and improve the sensitivity of these studies.
Sellen, Dr. Daniel William, U. of Toronto, Toronto, Ontario, Canada - To aid workshop on 'Cross-Cultural Comparisons in Early Postnatal Care Practices,' 2007, Mbulu District, Tanzania, in collaboration with Dr. Crystal Lauren Patil
'Cross-Cultural Comparisons in Early Postnatal Care Practices'
November 25-28, 2008, Haydom Lutheran Hospital, Mbulu District, Tanzania
Organizers: Daniel Sellen (University of Toronto) and Crystal Patil (University of
Illinois - Chicago)
Twenty-five anthropologists, community development workers, nutritionists, nurses, and physicians from around the world came together at this workshop to discuss the cultural and health-related aspects of diversity in early postpartum care practices and maternal, neonatal, infant, and child health in ethnically diverse communities in East Africa. Collaborating
institutions included the host hospital and universities in Tanzania, Norway, Canada, and the United States. The workshop aimed to be innovative in its focus on the applied anthropology of early child care and on local issues in global context. Presentations, facilitated discussions, hospital rounds, and cultural tours facilitated structured academic exchange designed to develop new theory, methods, and indicators to document, describe, and compare key aspects of early child care practices that vary with socio-cultural, economic, ecological, and individual factors and are linked to health outcomes. A consensus on emerging practical and theoretical topics and current knowledge gaps was established and is being used as a basis for developing specific research collaborations in Tanzania among sub-groups of the participants.
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.
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.