Kuzawa, Dr. Christopher, Northwestern U., Evanston, IL - To aid research on 'Developmental Plasticity of Male Reproductive Ecology and Life History'
DR. CHRISTOPHER KUZAWA, Northwestern University, Evanston, Illinois, received funding in December 2005 to aid research on 'Developmental Plasticity of Male Reproductive Ecology and Life History.' Dr. Kuzawa and an international team from Northwestern University, the University of North Carolina (Chapel Hill), and the University of San Carlos (the Philippines), investigated whether fetal and infant nutrition and growth influence male reproductive biology (morning and evening salivary testosterone; luteinizing hormone measured in blood samples). They hypothesized that birth weight or length (measures of prenatal nutrition) and/or growth rate or diarrheal morbidity during infancy (postnatal nutrition) would predict adult testosterone levels. Participants included roughly 900 young adults in a long-term study of health in the Philippines. In this population, males born tall and skinny had highest T levels as adults. During infancy, how often an individual experienced the nutritional-stress of diarrhea predicted future T levels: the more nutritional stress early in life, the lower the production of T in adulthood. Similarly, weight gain during infancy, an indirect measure of nutritional sufficiency, was a strong positive predictor of adult T levels. These responses likely involve changes in regulation by the brain and also in testicular development. This study is significant as it is among the first to demonstrate how early life nutrition can have a lasting influence on the reproductive ecology of the adult male.
Garruto, Dr. Ralph M., State U. of New York, Binghamton, NY - To aid research on 'Longitudinal Studies of Health Transition and Culture Change in Vanuatu'
DR. RALPH M. GARRUTO, State University of New York, Binghamton, New York, received funding in April 2011 to aid research on 'Longitudinal Studies of Health Transition and Culture Change in Vanuatu.' Health burdens are changing in developing countries worldwide. Whereas chronic diseases such as hypertension and obesity were once primarily diseases of industrial countries, these now represent major health concerns in the developing world. Vanuatu, a South Pacific nation of 68 inhabited islands, is currently experiencing this change in disease patterns, or 'health transition.' Comparing chronic disease risk and population characteristics among islands could help to clarify how health transitions develop, and the social, behavioral, and economic factors driving the change. From June-August 2011, nearly 2000 individuals from five islands participated in surveys of behavioral, nutritional and economic patterns and body measurements (such as height, weight, and body fat). Preliminary results indicate that health patterns change in ways specific to the behaviors and economic conditions of each island and the degree of outside influence, regardless of geographic remoteness. Chronic disease risk is also influenced by the risk of infectious diseases, which impact not only an individual's phenotype, but also behavioral and economic factors (such as growth of the tourism industry) that in turn affect the population's health. This project contributes to our understanding of human biological variation across geographical regions and the factors that determine health outcomes in Pacific Island populations.
Bekelman, Traci Allison, U. of Colorado, Boulder, CO - To aid research on 'Using the Protein Leverage Hypothesis to Understand Socioeconomic Variation in Diet and Body Size,' supervised by Dr. Darna Dufour
Preliminary abstract: The primary objective of the proposed research is to provide insights into the factors responsible for the larger body size of urban Latin American women of low- versus high-socioeconomic status (SES). To accomplish this we intend to focus on dietary factors, of which surprisingly little is known, and specifically to test hypotheses derived from the Protein Leverage Hypothesis, a theoretical model developed by Simpson and Raubenheimer. Guided by the Protein Leverage Hypothesis, this study will test an explanation for the inverse relationship between SES and body size: limited access to dietary protein in low-SES women leads to a lower proportion of protein in the diet which, in turn, drives higher energy intake. To accomplish the research objective, anthropometry and weighed food records will be collected from 134 urban women in low- and high-SES neighborhoods in San José, Costa Rica. We will also examine perceived economic barriers to protein access using structured interviews and the strategies women use to overcome those barriers using a Geographic Information System (GIS). This research will generate new knowledge about how biology, culture and the physical and social environments interact to influence energy intake and body size.
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.
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.
Nelson, Dr. Robin Gair, Skidmore College, Saratoga Springs, NY - To aid research on 'Residential Context, Non-Kin Care and Child Health Outcomes in Jamaica'
DR. ROBIN G. NELSON, Skidmore College, Saratoga Springs, New York, was awarded a grant in April 2011 to aid research on 'Residential Context, Non-Kin Care and Child Health Outcomes in Jamaica.' This study explores the relationship between residential context, parental investment, and child health outcomes in Jamaica. It centers on an examination of the growth and development of children living in state-sponsored homes, and children who are living with biological family members. Ethnographic, anthropometric, and biometric data were collected from 125 children living in state-sponsored children's homes, and 119 children living with their biological family members in Manchester Parish. Follow-up data were collected from 70 of 125 children who were still living in childcare facilities. Preliminary analyses reveal statistically significant correlations between residence in a state-sponsored care setting and anthropometric health indicators. There are also statistically significant gendered differences in the health outcomes between girls and boys living in these state-sponsored homes. These findings parallel ethnographic data detailing highly variable and gendered childcare practices in these homes. Future analyses will compare anthropometric and biometric data of children living with biological kin, and that of their peers living in the children's homes. These findings aid in our understanding of the ways that variability in kin investment and care setting come to correlate to particular health outcomes. This study navigates the intersection of evolutionary theory and biocultural studies of child care practices and health outcomes.
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
Preliminary abstract: 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 will be sampled from the three populated islands of the Galapagos and detailed survey data will be 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.