Biodemography has emerged and grown over the last fifteen years, with loyal and far-sighted support from its patrons. As it enters what might be called its adolescence as a field, it faces challenges along with abounding opportunities. One challenge is to continue to generate knowledge that contributes to human health and well-being. A second is to insist on high standards of quality control within its cross-disciplinary environment. Opportunities appear in a variety of directions, including mathematical modeling, genomic analyses, and field studies of aging in the wild.
1. Progress in Biodemography
The last 15 years have witnessed remarkable scientific progress in the emerging field of biodemography. Research in the biodemography of longevity has brought about a whole change in attitude with respect to future progress against mortality at extreme ages, shifting prevailing views from an emphasis on limits and diminishing returns to an emphasis on plasticity. The effect is seen in the solid consensus that has now crystallized around forecasts that posit a continuation of extensions in longevity, with strong implications for the future of social insurance systems in the United States, Europe, Japan, and other developed and developing countries.
The development of biodemography was made possible from the beginning by investments on the part of what is now the Behavioral and Social Research Division of the U.S. National Institute on Aging (N.I.A.) under the leadership of Richard Suzman. Its progress can be traced through a series of workshops funded by the N.I.A. and associated volumes sponsored by the N.I.A. under the auspices of the Committee on Population of the U.S. National Academy of Sciences.
Progress in the biodemography of longevity has been paced by a 1988 workshop at Berkeley organized by Sheila Johansson and chaired by KennethWachter, a pair of workshops in Irvine, California and Washington, D.C. and a 1997 volume Between Zeus and the Salmon edited by Kenneth Wachter and Caleb Finch, and a workshop on the Greek island of Santorini and 2003 volume Life Span edited by James Carey and Shripad Tuljapurkar. Scientific results have been summed up in a 2002 volume entitled Longevity by James Carey. Parallel work on the biodemography of fertility and family formation has led to workshops and a 2003 volume Offspring edited by Kenneth Wachter and Rodolfo Bulatao, sponsored by the U.S. National Institute of Child Health and Human Development. Today support for the field has become more international and includes an active program in evolutionary demography at the Max Planck Institute in Rostock, Germany.
Current thinking about trends in mortality draws on biodemographic insights, as in Wilmoth (2007). Complementary viewpoints from behavior genetics may be found in the collection edited by Rodgers and Kohler (2002). A perspective on the evolutionary questions addressed by biodemography has been offered by Flatt and Promislow (2007). Basic sources remain Finch (1990), Charlesworth (1994), Rose (1991), and Vaupel et al. (1998).
On a fundamental level, research in biodemography has challenged classical formulations of the evolutionary theory of longevity, both through experimental and observational data and through mathematical and theoretical developments. Initiatives in biodemography have also induced demographers and behavioral social scientists to learn about basic tenets and new findings in the genetics and biology of aging and begin to make biological realism a priority in models. Demographic perspectives have influenced research strategies for a select group of biologists who have come to recognize the value of large population studies for generating lifetable estimates, along with the need for comparative formal modeling. The experience of grappling with the evolutionary theory of longevity has led demographers into collaboration with anthropologists and helped recast our assumptions about the evolutionary environment in which genetic and biological determinants of agespecific vital rates have been shaped. …