Bio-demographic and evolutionary approaches to life history
Bio-demographic and evolutionary approaches to life history expands the vision of our program to incorporate biological and evolutionary frameworks for understanding the demography of aging. The variable expression of this approach depends on the disciplinary background of our Associates. We deliberately relate morbidity and mortality research to their biologic and evolutionary underpinnings in at least four ways. Researchers in the medical or epidemiologic tradition assume a direct linkage between risk factor and outcome. This approach dominates the work of Bowles, Kagan, Preston, and Trojanowski. The second way that biological factors are reflected in our work is by rationalizing cohort and period effects on morbidity and mortality. A prime example of this approach is Preston’s recent papers on the effect of smoking and obesity on future life expectancy in the US. Other Associates more directly consider biological factors as both markers of specific traits and risk factors for specific diseases. Tishkoff is investigating genetic variants of several health vulnerabilities and diseases in African populations. The work done among the Toba of Argentina by Valeggia points to the use of biomarkers to evaluate the response of indigenous populations to changes in diet and physical activity, particularly those that relate to chronic diseases. Fourth, our Associates are using an evolutionary framework to understand demographic patterns. An example of this approach is illustrated in the work of Fernandez-Duque, who uses non-human primates as a model for answering questions about how society influences life history trajectories. This theme is intimately related with one of the innovative networks we are proposing (EvoDemo Network).