Anthropological and evolutionary demography

Abstract

Demography was once a subfield of the social sciences dedicated to the statistical study of birth and death rates, and the mathematical description of these vital rates (function fitting). This also included an empirical examination of proximate factors that affect vital rates. Anthropological demography focused mainly on small-scale (non-Western) societies, and employed interpretations drawn from so-called "anthropological theory" (e.g., Howell, 1986; Campbell and Wood, 1998; Kertzer and Fricke, 1997; Bernardi, 2007). Cross-cultural comparisons were a mainstay of the field. In the past thirty years, however, anthropological demography changed significantly to become a theoretically informed study of mortality and fertility, and other age-related biological features. The theory is based on an evolutionary perspective that can unite human demographic studies with those of other primates, mammals and vertebrate species (e.g., Hill, 1993; Kaplan, 1996; Vaupel, 2010, Blurton-Jones, 2016). This transition expanded the field from the study of vital rates to one including research on growth, development, ageing patterns, etc. (physiological, cognitive, emotional mechanisms) that are strongly theoretically tied to mortality and fertility schedules (e.g., Ketterson and Nolan, 1992; Rickleffs and Wikelski, 2002; Kaplan and Gangestad, 2005; Kirkwood and Austad, 2000). These important changes in the field emerged primarily from the injection of life history theory from biology into the social sciences. A fundamental proposition of evolutionary biology is the recognition that fertility and mortality are the two components of individual fitness. Hence, all phenotypic adaptations that act on one or both of these components will evolve via natural selection. From this view, it is clear that the mechanisms of fertility and survival are key biological adaptations and can only be fully understood in the context of evolution.