Valeggia, Dr. Claudia R., CONICET, Formosa, Argentina - To aid research on 'Fertility Patterns and Energy Availability of Foraging Wichi in the Argentine Chaco'
DR. CLAUDIA R. VALEGGIA, CONICET, Formosa, Argentina, was awarding a grant in May 2003 to aid research on 'Fertility Patterns and Energy Availability of Foraging Wichi in the Argentine Chaco.' This study was part of the Chaco Area Reproductive Ecology Program, a long-term project that seeks to understand the interactions between environment, behavior, and reproductive biology of foraging groups in the Argentine Chaco. The aim of the study was to collect baseline data on how demographic and fertility patterns of Wichí people (n = 800) relate to changes in seasonal variation in energy availability and foraging practices. Preliminary results indicate a high fertility rate (8.6 births per woman), a relatively short inter-birth interval (average: 2.3 months 3.6) and a high infant mortality rate (46%). A birth seasonality effect was evident, with conceptions taking place between April and July. The Wichí of these communities were in good nutritional status, only 2% of adults (all women) were considered undernourished. Furthermore, there was a considerable percentage of overweight and obesity. As many as 55% of men and 54% of women were overweight (Body Mass Index > 25), whereas 17% of both men and women were obese (BMI >30). There were no apparent differences in energy availability across the annual cycle. However, there was considerable seasonal variation in the frequency and type of subsistence activities and in diet composition. A marked sexual division of activities was also evident and that seems to explain the differences in energy availability between women and men. Further analyses will explore the interaction between seasonality, division of labor, and fertility.
Astorino, Claudia Marie, City U. of New York, Lehman College, New York, NY - To aid research on 'Does Human Sex Indicator Morphology in the Skull Co-vary With Age and Ancestry?,' supervised by Dr. Eric Delson
Preliminary abstract: While it is generally accepted that levels of human sexual dimorphism (HSD) vary across geographic populations, few systematic studies have attempted to quantify how age and ancestry influence population-specific ranges of variation. This study will determine if and how the expression of sexually dimorphic traits in the skull co-varies with age and ancestry both within and among contemporary human populations. Gaining a greater understanding of HSD ranges is integral to testing hypotheses about modern human variation and the hominin fossil record. Sex estimation is one of the first analyses performed on recent or fossil remains, where sex estimates are then used to estimate other biological variables (e.g., age, ancestry, stature), infer sociocultural variables in recent humans (e.g., status, occupation), and reconstruct aspects of hominin evolution (e.g., phylogeny, life history). However, most standard sex estimation techniques have been developed on middle-aged, white, Western samples whose demographics may greatly differ from test populations of interest. The most informative bony indicators for accurate sex estimation may differ among populations defined by ancestry and some indicators may be more accurate than others at different ages within populations. Greater knowledge of the relationship of age and ancestry to ranges of HSD will increase sex estimation accuracy. Some recent studies of HSD have utilized 3D geometric morphometric (GM) methods to quantify overall skull shape, but few have applied semilandmark methods to quantify shape differences in regions with few homologous landmarks. This study will utilize such a semilandmark 3D GM approach along with discriminant function analysis for this purpose.
Kaestle, Dr. Frederika A., Indiana U., Bloomington, IN; and Ribeiro-Dos-Santos, Andrea, U. Federal do Para, Belem, Brazil - To aid collaborative research on 'mtDNA in Brazilian Prehistoric Groups of the Last 12,000 Years'
Vento, Melanie, Northwestern U., Evanston, IL - To aid research on 'Evolutionary Perspectives on the Emergence of Chronic Metabolic Diseases in an Amazonian Bolivian Population,' supervised by Dr. William R. Leonard
MELANIE VENTO, then a student at Northwestern University, Evanston, Illinois, was awarded funding in May 2008 to aid research on 'Evolutionary Perspectives on the Emergence of Chronic Metabolic Diseases in an Amazonian Bolivian Population,' supervised by Dr. William R. Leonard. This research among the Tsimane' builds on recent findings to shed light on why transitional populations may experience greater risk of obesity and chronic disease under conditions of rapid social change. The recent finding that inflammation -- an immune process stimulated by both infection and obesity -- is integral to cardiovascular disease (CVD) suggests that individuals in transitional populations (experiencing both pathogenic physical environments and weight gain) will face a double burden of harmful inflammatory stimuli, placing them at greater risk for CVD. Furthermore, for developing populations, the joint effects of under-nutrition and high infectious disease load in childhood may contribute to both small body size and depressed metabolic rates leaving adults particularly at risk for the development of obesity and associated chronic disorders when exposed to a more urbanized diet and lifestyle. This study integrates these perspectives to test a novel model for the role of population adaptation in the rise of chronic disease under conditions of social change. Adopting the developmental origins of health and disease framework, which recognizes the importance of early life adaptive physiological changes to a predicted future environment, the research investigates the roles that diet, activity, metabolism, and inflammation play in chronic disease risk when increased market exposure leads to shifts in nutritional status across the life course. More specifically, the study examines: 1) how greater market integration is associated with adult weight gain and chronic disease risk; 2) the role of adiposity, infection, and pathogenicity on inflammation (C-reactive protein levels); and 3) whether the combined influence of poor early nutritional environments (indicated by leg length), low metabolism and small size place Tsimane' at greater risk for obesity and CVD in adulthood.
Barta, Dr. Jodi Lynn, U. of Toronto, Mississauga, Canada - To aid research on 'The Relationship Between Skin Pigmentation and Vitamin D Insufficiency in Northern Latitudes'
DR. JODI LYNN BARTA, University of Toronto, Mississauga, Canada, received funding in October 2007 to aid research on 'The Relationship between Skin Pigmentation and Vitamin D Insufficiency in Northern Latitudes.' This project examined the effects that changes in season have on vitamin D concentrations in individuals with varying levels of melanin in their skin in order to clarify the relationship between constitutive pigmentation and vitamin D status in otherwise healthy young adults of diverse ancestry living in northern latitudes. Preliminary data collected show that those with higher levels of melanin in their skin are at consistently higher risk of vitamin D insufficiency and deficiency, thus supporting the UVR hypothesis and highlighting the evolutionary significance of skin pigmentation as it relates to geographic origins and the importance of maintaining adequate vitamin D levels. Given the profound effects that vitamin D insufficiency and deficiency have on the human body, it was surprising that mean vitamin D concentrations in all ancestry groups were below adequate (75 nmol/L) regardless of season, despite the fact that mean vitamin D intakes in both late summer (296.72 IU) and winter (281.54 IU) were above current recommended adequate intake for adults (200 IU/day). Further research is necessary to precisely determine the vitamin D requirements of individuals of diverse ancestry living in northern latitudes and address the need for higher vitamin D intakes through supplementation and/or improved food fortification strategies to meet requirements and improve overall public health.
Froehle, Andrew William, U. of California, San Diego, La Jolla, CA - To aid research on 'Physical Activity and Basal Metabolic Rate in Postmenopausal Women,' supervised by Dr. Margaret J. Schoeninger
ANDREW WILLIAM FROEHLE, then a student at University of California - San Diego, La Jolla, California, received a grant in October 2007 to aid research on 'Physical Activity and Basal Metabolic Rate in postmenopausal Women,' supervised by Dr. Margaret J. Schoeninger. The project investigated the relationship between age, exercise and basal metabolic rate (BMR) in postmenopausal women, comparing two subgroups: 'active' (>5 hours exercise/week) and 'training' (sedentary at baseline, completed four-month exercise program). Across the entire sample, BMR correlated significantly with fat free mass (FFM; P<0.001, R=0.862) and physical activity level (PAL; P=0.004, R=0.542), but not with age or maximal aerobic capacity (VO2MAX). At baseline, subgroups differed significantly for BMR (P=0.005) and VO2MAX (P=0.006); active women were also 4.9 kg heavier (FFM) than sedentary women (not significant: P=0.077). Within the active group, no variables changed significantly over the study period. Meanwhile, the training sample exhibited significant increases over baseline in VO2MAX (P=0.015) and BMR (P=0.002), despite no change in FFM (P=0.952). Controlling for effects of the covariate FFM, subgroups differed significantly for BMR at baseline (P=0.007), but not at the end of the study (P=0.089). Results suggest that in this population, both short- and long-term exercise associate similarly with elevations in BMR above sedentary levels. Contrary to some research, this may not be tied to increased FFM. These results have implications for preventative exercise prescription against age-related health risks, and will help refine models of metabolic physiology in active postmenopausal women.
Froehle, Andrew W., S.R. Hopkins, L Natarajan, and M.J. Schoeninger. 2013. Moderate to High Levels of Exercise are Associated with Higher Resting Energy Expenditure in Community-dwelling Postmenopausal Women. Applied Physiology, Nutrition, and Metabolism 38(11):1147-1153.
Klein, Laura Danielle, Harvard U., Cambridge, MA - To aid research on 'Impacts of Maternal Disease Ecology on Milk Immunofactors and Infant Immune System Development,' supervised by Dr. Katherine J. Hinde
Preliminary abstract: Mothers' milk provides crucial immunological protection to the infant during early life. However, little is known about how the immune molecules that are present in milk vary among women living in vastly different nutritional, disease, and cultural ecologies. This project will use a longitudinal study in a population of small-scale agriculturalists at the Mogielica Human Ecology Study Site in southern Poland to investigate how aspects of the local environment, including diet and disease exposure, relate to the variation in composition of immune factors in breast milk within a population. This project will also examine how variation in mothers' milk might influence infant immune system development by taking advantage of a regularly schedule vaccine that mimics a natural immune challenge.