Escasa, Michelle Jickain, U. of Nevada, Las Vegas, NV - To aid research on 'Female Sociosexuality, Mate Preferences, and Sex Steroid Hormones of Lactating Women in Manila,' supervised by Dr. Peter B. Gray
MICHELLE J. ESCASA, then a student at University of Nevada, Las Vegas, Nevada, received a grant in April 2011 to aid research on 'Female Sociosexuality, Mate Preferences, and Sex Steroid Hormones of Lactating Women in Manila,' supervised by Dr. Peter B. Gray. This project investigates the influence of lactation on female sociosexuality and mate preferences in urban Manila, a population with long-term breastfeeding, low contraceptive use, and quick return to cycling. From an evolutionary perspective, female ancestors were likely spending more time pregnant and lactating rather than ovulating. Moreover, a majority of conceptions in natural fertility societies occurred in lactating, ovulating women. These considerations suggest that lactating women face important life history allocation trade-offs between mating and parenting effort that may be manifested in their sociosexual behavior and mate preferences. Breastfeeding (n=155) and control (n=105) women were recruited to provide a saliva sample (for testosterone and estradiol analyses) and complete a face and voice preference task to determine preferences for masculinity. All participants also completed a questionnaire that assessed sexual functioning, sociosexuality, and relationship satisfaction, along with demographic variables. Breastfeeding women report differences in commitment to their relationship, jealousy levels, sexual functioning, and preferences for high-pitched voices. Further analyses incorporate the age of the infant and the cycling status of participants. Cultural and life history factors will be discussed and will serve as a framework for the findings.
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.
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.
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.
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.