Excerpt

This volume takes stock of what biology and demography have to tell and ask each other about human longevity as we move into the Third Millennium. The timing is auspicious. First, recently published works have made the base of accumulated biological knowledge accessible. Finch (1990) has written an authoritative summary of the comparative biology of senescence. Charlesworth (1994) and Rose (1991) have covered evolutionary theory for aging, and Steams (1992) has covered organism life-history analysis. A historical perspective has been given by Olshansky and Carnes (1997). Second, the initial harvest of results from program projects combining biology and demography sponsored by the U.S. National Institute on Aging has just reached the scientific literature. The remarkable hazard functions for a million Mediterranean fruit flies (Carey et al., 1992) and for genetically uniform populations of Drosophila (Curtsinger et al., 1992) are prominent examples. Now is the moment for planning the next waves of joint research. Third, forecasting survival and health for the oldest-old over the next 50 years has become an urgent political need, as developed societies try to plan for avoiding bankruptcy for their social insurance and medical systems. Our uncertainty as to whether current trends will continue or taper is bound up with our uncertainty about the general nature of biological limits to longevity.

Contents

• The National Academies
• COMMITTEE ON POPULATION
• Preface
• 1. Between Zeus and the Salmon: Introduction
  • Stern Theories
  • Empirical Challenges
  • The Elderly In Nature
  • Theoretical Departures
  • The Promise Of Future Research
  • References
• 2. Trajectories of Mortality at Advanced Ages
  • Theories About Mortality At Advanced Ages
  • Empirical Findings
  • Mechanisms
  • Bio-Reliability Theory
  • The Evolutionary Theory Of Aging Revisited
  • Conclusion
  • References
• 3. In Search of Limits
  • Introduction
  • What would limits to human longevity look like?
  • Conclusion
  • References
• 4. The Evolution of Senescence
  • Introduction
  • Evolutionary Equilibria
  • Two Evolutionary Equilibria
  • Other Equilibria
  • Directions
  • Acknowledgments
  • References
• 5. Evolutionary Biology and Age-Related Mortality
  • Introduction
  • Age-Related Changes Within Individuals
  • Environmental Effects
  • Individual Variation
  • Interactions
  • Broader Implications Of An Evolutionary Approach For Human Aging
  • Conclusions
  • References
• 6. Toward an Evolutionary Demography
  • Introduction
  • Basic Theory Of Evolutionary Demography
  • Empirical Evidence Concerning the Force of Natural Selection
  • Theoretical Population Genetics Of Life-History Evolution
  • Experimental Population Genetics Of Life-History Evolution
  • Gompertz Models: Phenomenological Theory
  • The Oldest Old
  • Conclusion
  • Acknowledgments
  • References
• 7. Identification and Mapping of Genes Determining Longevity
  • Introduction
  • Concept Of Gerontogenes
  • Methods For Identifying Gerontogenes
  • Review of QTL Mapping of Longevity
  • Cloning The Genes
  • Genetics of age-specific mortality in c. Elegans
  • Conclusions
  • References
• 8. Population Biology of the Elderly
  • Introduction
  • Foundational Concepts
  • The Elderly In Nature: Selected Case Studies
  • Extended Longevity As A Preadaption For Eusociality
  • Discussion
  • Acknowledgments
  • References
• 9. Postreproductive Survival
  • Postreproductive Survival In Nature
  • The Role Of The Elderly In Nature
  • References
• 10. The Evolution of the Human Life Course
  • Introduction
  • Human And Nonhuman Primate Life Histories: Fundamental Characteristics
  • A General Model For The Evolution Of Life Histories
  • Menopause, Longevity, And The Postreproductive Period
  • Historical, Current, And Future Trends In Morbidity And Mortality
  • Summary And Conclusions
  • References
• 11. Intergenerational Relations and the Elderly
  • Introduction
  • Prevalence Of The Elderly In Human Populations—Actual, Historical, And Projected
  • The Elderly As Repositories Of Knowledge
  • Transfer Flows To And From The Elderly
  • The Transfer Of Assets: Bequests
  • Conclusion
  • Acknowledgment
  • References
• 12. The Potential of Population Surveys for Genetic Studies
  • Introduction
  • Summary Of Recent NIA Population-Based Surveys
  • Potential Applications Of Population Surveys For Genetic Study
  • Collecting Genetic Information In Population Surveys
  • Ethical Considerations In The Acquisition And Storage Of Genetic Specimens
  • Potential Enhancements To NIA-Sponsored Surveys To Improve Applications To Genetic Studies
  • Conclusion
  • References
• 13. Comparative Perspectives on Plasticity in Human Aging and Life Spans
  • Introduction
  • The Million-Fold Range Of Life Spans
  • Plasticity In Senescence
  • Cell Proliferation And Life-History Plasticity
  • Molecular Age Changes And Plasticity
  • Prospects For A Genetics Of Longevity
  • Acknowledgment
  • References
• Glossary

This study was supported by Contract No. N01-OD-4-2139 between the National Academy of Sciences and the National Institute on Aging.

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the organizations or agencies that provided support for this project.

NOTICE: The project that is the subject of this report was approved by the Governing Board of the National Research Council, whose members are drawn from the councils of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. The members of the committee responsible for the report were chosen for their special competences and with regard for appropriate balance.