Journal Article

Extrinsic mortality can shape life-history traits, including senescence

Dańko, M. J., Burger, O., Argasiński, K., Kozłowski, J.
Evolutionary Biology, 45:4, 395–404 (2018)
Open Access


The Williams’ hypothesis is one of the most widely known ideas in life history evolution. It states that higher adult mortality should lead to faster and/or earlier senescence. Theoretically derived gradients, however, do not support this prediction. Increased awareness of this fact has caused a crisis of misinformation among theorists and empirical ecologists. We resolve this crisis by outlining key issues in the measurement of fitness, assumptions of density dependence, and their effect on extrinsic mortality. The classic gradients apply only to a narrow range of ecological contexts where density-dependence is either absent or present but with unrealistic stipulations. Re-deriving the classic gradients, using a more appropriate measure
of fitness and incorporating density, shows that broad ecological contexts exist where Williams’ hypothesis is supported.

The Max Planck Institute for Demographic Research (MPIDR) in Rostock is one of the leading demographic research centers in the world. It's part of the Max Planck Society, the internationally renowned German research society.