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.
Rosinger, Asher Yoel, U. of Georgia, Athens, GA - To aid research on 'Hydration Strategies, Nutrition, and Health During a Lifestyle Transition in the Bolivian Amazon,' supervised by Dr. Susan Tanner
ASHER Y. ROSINGER, then a student at University of Georgia, Athens, Georgia, received a grant in April 2013 to aid research on 'Hydration Strategies, Nutrition, and Health during a Lifestyle Transition in the Bolivian Amazon,' supervised by Dr. Susan Tanner. Currently, many Amazonian populations are undergoing a period of rapid change in lifestyle through increased market participation and dietary changes, yet the search for clean water remains a critical problem facing many of these populations. The social sciences emphasize that when populations undergo lifestyle transitions, health, disease patterns, and body composition are affected. Lifestyle transitions may create a mismatch between hydration strategies and the nutritional landscape. This research found that Tsimane' have flexible hydration strategies that rely on their environment for water. Increased water intake from foods was associated with a decreased risk of diarrheal illness among adults, which may represent a nutritional adaptation to an environment with limited access to clean water. Tsimane' who lived in a market integrated community were significantly more dehydrated than Tsimane' living in a traditional community. These findings contribute to human biology theory by suggesting that lifestyle transitions may create conditions that increase vulnerability to dehydration among rural populations. Additionally, lactating women were significantly more dehydrated than non-lactating women controlling for environmental and lifestyle factors. This work illustrates the nutritional challenges lactating women face in stressful physical environments and raises evolutionary questions dealing with maternal buffering during chronic dehydration.
Rosinger, Ascher. 2015. Heat and Hydration Status: Predictors of Repeated Measures of Urine Specific Gravity Among Tsimane' Adults in the Bolivian Amazon. American Journal of Physical Anthropology 158(4):696-707
Rosinger, Asher. 2014. Water from Fruit or the River? Examining Hydration Strategies and Gastrointestinal Illness among Tsimane' Adults in the Bolivan Amazon. Public Health Nutrition. (Published Online, DOI 10.1017/s1368980014002158)
Rosinger, Asher. 2014. Dehydration among Lactating Mothers in the Amazon: A Neglected Problem. American Journal of Human Biology. (Published Online.DOI 10.1002/ajhb.22672)
Betti, Lia, U. of Kent, Canterbury, United Kingdom - To aid research on 'Out of Africa and What Happened Next: Exploring the Origins of Human Pelvic Shape Variability,' supervised by Dr. Noreen von Cramon-Taubadel
LIA BETTI, then a student at University of Kent, Canterbury, United Kingdom, received a grant in April 2011 to aid research on 'Out of Africa and What Happened Next: Exploring the Origins of Human Pelvic Shape Variability,' supervised by Dr. Noreen von Cramon-Taubadel. The origin of human morphological diversification is one of the most intriguing questions in human evolution. Starting from a single origin of the species, how did the current pattern of morphological diversity between populations develop? Recent studies on cranial shape variation disclosed a very strong signature of the Out Of Africa expansion of our species on the global pattern of morphological diversity. This study builds upon this knowledge and explores the foundation of pelvic shape variation. Being involved in locomotion, childbirth, and potentially subject to climatic factors, the pelvis is a key anatomical region in studies of human biology and evolution. 3D pelvic morphometric data were collected from 27 globally distributed modern human populations. An explicit population genetic approach was used to explore the effect of different evolutionary factors on the global pattern of variation, revealing a strong signature of ancient demographic history on pelvic shape variation, with climatic adaptation and obstetrical constraints playing a secondary role.
Betti, Lia. 2014. Sexual Dimorphism in the Size and Shape of the Os Coxae and the Effects of Microevolutionary Processes. American Journal of Physical Anthropology 153(2):167-177.
Fujita, Masako, U. of Washington, Seattle, WA - To aid 'An Evolutionary Perspective on Mother-Offspring Vitamin A Transfer,' supervised by Dr. Bettina Shell Duncan
MASAKO FUJITA, then a student at University of Washington, Seattle, Washington, was awarded a grant in April 2006 to aid research on 'An Evolutionary Perspective on Mother-Offspring Vitamin A Transfer,' supervised by Dr. Bettina Shell-Duncan. This project investigated the perplexing decline in breastmilk vitamin A (VA) concentrations across the postpartum months. Applying the concept of life-history tradeoffs, this decline was hypothesized to be an evolved maternal reproductive strategy optimizing physiological reallocation of VA between competing needs of current and future reproduction depending on postpartum time and reproductive status. The hypotheses were tested using breastmilk VA and maternal hepatic VA data, collected among 250 lactating Ariaal mothers in northern Kenya, as indices for maternal investment respectively on current reproduction and future reproduction. Data indicated maternal hepatic VA is in a trade-off relationship with milk VA postpartum. Breastmilk VA does not track hepatic VA but instead declines despite increasing hepatic stores in the late postpartum period. Results shed light on the evolutionary ecological heritage of human micronutrient metabolism and human reproduction, and further illuminate policy directions for currently recommended public health strategy of high-dose postpartum maternal VA supplementation.
Fujita, Masako, Eric Roth, Yun-Kia Lo, Carolyn Hurst, Jennifer Vollner, and Ashley Kendell. 2012. In Poor Families, Mothers' Milk is Richer for Daughters than Sons: A Test of Trivers-Willard Hypothesis in Agropastoral Settlements in Northern Kenya. American Journal of Physical Anthropology 149(1):52-59.
Houck, Kelly Marie, U. of North Carolina, Chapel Hill, NC - To aid research on 'A New Dual Burden Life History Theory Application Exploring Childhood Gut Immune Function and Overnutrition,' supervised by Dr. Amanda Thompson
KELLY HOUCK, then a graduate student at University of North Carolina, Chapel Hill, North Carolina, was awarded funding in April 2014 to aid research on 'A New Dual Burden Life History Theory Application Exploring Childhood Gut Immune Function and Overnutrition,' supervised by Dr. Amanda Thompson. The emerging field of gut microbiota contributes to anthropological concerns by providing a new pathway to examine the effects of pathogenic, nutritional, and social environments on human physiology and consequently human variation. The bacterial components and metabolites of gut microbial communities are vital factors in the regulation of the immune system and in providing energy processing. This project develops and tests a new application of childhood life history theory tradeoffs in maintenance and growth for the dual burden environment through a focus on gut immune function. This framework incorporates the increased energetic cost of both dietary- and pathogenic-induced immune activation and models the influence of gut immune function on diverting resources from linear bone growth towards adiposity. Children were sampled from San Cristobal Island, Galapagos, and detailed survey data was collected on their diet, symptom history, sociodemographics and household sanitation, along with anthropometric assessments, household water quality tests, and blood spot and fecal analyses of gut immune function biomarkers. Data will be used to test for the relationship between overnutrition and infection on gut immune activation and to determine the cost of pathogenic and dietary immune activation on tradeoffs in adiposity and linear growth.
Maxfield, Amanda Leigh, Emory U., Atlanta, GA - To aid research on 'A Biocultural Study of the Links Between Food Insecurity and Mental Health in India,' supervised by Dr. Craig Hadley
Preliminary abstract: Food insecurity-- uncertain access to sufficient food to maintain a healthy and active life-- negatively affects both physical and mental wellbeing. The majority of research on food insecurity focuses on the biological value of food for health, but food has both biological and cultural importance for humans. This project will examine the role that the social meaning of food plays in linking food insecurity to mental wellbeing. Specifically, this research tests the possibility that individuals literally consume the cultural meaning attached to different foods, and that this embodied meaning influences biological processes like stress that ultimately impact mental health. Globalization and the nutrition transition introduce new foods and food-related behaviors to communities around the world. A growing body of research demonstrates that relative inequality may be as detrimental to wellbeing as absolute income. This project will examine whether the changing dietary landscape in India sets food insecure individuals up for aspirational failure, by introducing them to a wide variety of foods they can never or rarely expect to attain. Specifically, this research will examine whether exposure to novel and global foods heightens feelings of relative food insecurity, thereby harming mental health.
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.
Fujita, Dr. Masako, Michigan State U., East Lansing, MI - To aid research on 'The Impact of Maternal Nutrition and Infant Sex on Breast Milk Quality in Polygynous Ariaal Agro-pastoralists of Northern Kenya'
Preliminary abstract: The Trivers-Willard hypothesis (TWH) predicts unequal parental investment between daughters and sons in polygynous populations where somatic or economic conditions of males determine their marriageability. Specifically, it predicts that mothers in good condition will invest more in sons while mothers in poor condition will invest more in daughters because these strategies may enhance their reproductive success. A small but growing number of studies investigate sex bias in human milk quality, particularly milk nutrient levels with mixed results. This literature focuses on energy-yielding nutrients (e.g. fat, sugar) to test the hypothesis, and misses other nutritive and non-nutritive components of milk indispensable for infants to survive and thrive. The proposed study contributes by examining TWH, using breast milk vitamin (B9 or folate) and antibody (secretory immunoglobulin A or sIgA) as indicators of maternal investment. A cross-sectional random sample of breast milk specimens from 220 mothers of the Ariaal tribe, a polygynous population of rural Kenya, originally collected in 2006, cryogenically archived (-80°C), will be analyzed for the levels of folate-binding protein and sIgA. The resulting data will be used to statistically test the hypotheses: 1) maternal nutrition (e.g. adiposity, micronutrient status) will positively predict folate/sIgA, 2) this effect will be moderated by infant sex, and 3) there will be a TW effect, i.e. milk of under-nourished mothers will exhibit preference toward daughters and milk of other mothers toward sons. Findings will facilitate a multi-faceted view on possible sex bias in human milk components in a specific sociocultural and ecological context. This will contribute to the refined understanding of the conditional variation in human parental investment which has important implications for sex differences in infant growth and health in relation to different marriage rules.