Rethinking the evolutionary theory of aging: transfers, not births, shape senescence in social species

Proc Natl Acad Sci U S A. 2003 Aug 5;100(16):9637-42. doi: 10.1073/pnas.1530303100. Epub 2003 Jul 23.


The classic evolutionary theory of aging explains why mortality rises with age: as individuals grow older, less lifetime fertility remains, so continued survival contributes less to reproductive fitness. However, successful reproduction often involves intergenerational transfers as well as fertility. In the formal theory offered here, age-specific selective pressure on mortality depends on a weighted average of remaining fertility (the classic effect) and remaining intergenerational transfers to be made to others. For species at the optimal quantity-investment tradeoff for offspring, only the transfer effect shapes mortality, explaining postreproductive survival and why juvenile mortality declines with age. It also explains the evolution of lower fertility, longer life, and increased investments in offspring.

MeSH terms

  • Adaptation, Physiological
  • Aging*
  • Animals
  • Biological Evolution*
  • Demography
  • Economics
  • Environment
  • Fertility
  • Humans
  • Life Expectancy
  • Longevity
  • Models, Theoretical
  • Parturition
  • Population Dynamics
  • Population Growth
  • Reproduction