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.
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'
Paschetta, Carolina Andrea, U. Nacional de Rio Cuarto, Puerto Madryn, Argentina - To aid research on 'Dietary Shifts During Modem Human Evolution and their Effect on Craniofacial Size and Shape,' supervised by Dr. Rolando Gonzalez-Jose
Preliminary abstract: The craniofacial phenotype can suffer changes promoted by epigenetic or environmental factors. Among them, masticatory mechanical stress is perhaps one of the most important epigenetic stimuli which acted during the recent evolution of our species. In particular, technological transition from hunting-gathering is invoked to be concomitant with a significant reduction of masticatory stress. The main objective is quantify the differences in modern human samples with different economic strategies (hunter/gatherers, farmers, etc.), not only in the overall skull morphology, as well as in localized structures, in order to detect common, recurrent changes in craniofacial size and shape due to environmental stimuli. A geometric morphometrics techniques will be used to track these changes on at least three cases of economic transitions on New World populations. Changes observed in concomitance on all the transitions will be, in consequence, postulated as good candidates of plastic structures which probably promoted rapid evolution of modern humans across different adaptive (dietary, nutritional) shifts.
Vitzthum, Dr. Virginia Judith, State U. of New York, Binghamton, NY - To aid research on 'Testing Hypotheses of the Dietary Determinants of Ovarian Hormones: A Comparative Study of Three Populations'
DR. VIRGINIA J. VITZTHUM, Institute of Primary and Preventative Health Care, Binghamton University, Binghamton, New York, was awarded a grant in May 2006 to aid research on 'Testing Hypotheses of the Dietary Determinants of Ovarian Hormones: A Comparative Study of Three Populations.' This research is part of a larger project to elucidate the ecological, behavioral, and ontogenetic determinants of variation in women's reproductive functioning. This phase of the project evaluated the relative importance of total caloric intake versus dietary fat consumption in determining ovarian steroid variation by comparing hormone levels in nomadic-herding Mongolian women (high fat/low calorie diets) with those in previously collected samples of agropastoral Bolivian women (low fat/low calorie diets) and Chicago women (high fat/high calorie diets). Daily biological samples spanning a menstrual cycle and data on covariates were collected from 40 nomadic Mongolian women during July through September 2006. Assays were conducted in collaboration with Dr. Tobias Deschner at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. Initial analyses suggest that ovarian steroid levels are at least as high as those of U.S. women, suggesting that dietary fat may be the more important factor. In addition to increasing current understanding of the sources of variation in ovarian functioning, this finding suggests that the modulation of reproductive functioning during a woman's lifespan may be sensitive to variation in dietary fat intake. Ongoing research includes the collection of a comparative sample of German women and planned research includes genetic analyses to ascertain the potential contribution of genotypic variation to hormonal variation.
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.