Evolutionary Demography Society

The Evolutionary Demography Society, founded in 2013, is a scientific organization that is focused on conceptual integration across disciplines, most notably human demography and evolutionary biology (but also ecology, sociology, anthropology, epidemiology, public health).

Both demography and evolutionary biology are quantitative studies of population processes. Human populations are currently undergoing profound changes in age-structure, age-patterns of mortality and life expectancy with significant societal and public health consequences. Ever since Gompertz (1825), there is a general notion that human mortality increases with chronological age due to inescapably ever-declining physiological function. Nonetheless, across the tree of life there are diverse patterns of mortality; many species regularly experience the lowest mortality risk at the oldest ages.

Is it relevant to know which life circumstances/ causal/ mathematical mechanisms are associated with which patterns of mortality and where humans fit in? How is it that chronological age is irrelevant to physiological age in some species? Can understanding mortality patterns of organisms where these are decoupled shed light on some aspects of human ageing as well?

The comparative study of the evolution of such diverse "life histories", the timing of key events and differential allocation to growth, survival or reproduction, throughout the life cycle are relevant.

​Fertility, mortality, morbidity schedules of populations reflect the aggregate of variation in individual trajectories. At issue for both human and nonhuman populations are the causes and consequences of variation in these trajectories within and among populations, species, and lineages.

In fact, even human mortality trajectories, when considered from birth, do not show a paradigmatic monotonic rise in risk of mortality throughout life. Indeed there is a characteristic "bathtub shape" to human mortality from hunter-gatherer through modern populations, where the lowest risk of mortality is in the late teen years and there appears to be an observed mortality plateau at extremely old ages, although its meaning and origin are at issue. More people are now living to such extremely old ages; are they entering the plateau (Barbi et al. 2018)?

Relevant research foci include sources of variability (genetic, epigenetic, environmental and stochastic) among individuals in mortality, fertility and morbidity schedules across the life cycle in both human and nonhuman populations. Included in the field of evolutionary demography as well are the relative roles of biological measurements and non-biological measurements (e.g. socioeconomic) on humans related to age, health, physical functioning, and fertility.

References

Barbi, E., Lagona, F., Marsili, M., Vaupel, J. W., & Wachter, K. W. (2018). The plateau of human mortality: Demography of longevity pioneers. Science, 360(6396), 1459-1461.

​Carey, J. R. & Vaupel, J. W. 2019. Biodemography. In: Poston, D. & Micklin, M. (eds.) Handbook of Population. 2 ed. New York: Kluwer Academic/Plenum Publishers.

Gompertz, B. 1825. XXIV. On the nature of function expressive of the law of human mortality and on a new mode of determining the value of life contingencies. in a letter to Francis Baily. Phil. Trans. R. Soc. Lond. 1825 vol. 115 513-583.