A Unifying Framework for Estimating Generation Time in Age-Structured Populations: Implications for Phylogenetics and Conservation Biology
Journal article, 2022

Generation time is a measure of the pace of life and is used to describe processes in population dynamics and evolution. We show that three commonly used mathematical definitions of generation time in age-structured populations can produce different estimates of up to several years for the same set of life history data. We present and prove a mathematical theorem that reveals a general order relation among the definitions. Furthermore, the exact population growth rate at the time of sampling influences estimates of generation time, which calls for attention. For phylogenetic estimates of divergence times between species, included demographic data should be collected when the population growth rate for each species is most common and typical. In conservation biology, demographic data should be collected during phases of population decline in declining species, contrary to common recommendations to use predisturbance data. The results can be used to improve the International Union for Conservation of Nature’s recommendation in parameterizing models for evaluating threat categories of threatened species and to avoid underestimating extinction risk.

theoretical biology

population extinction risk

phylogenetics

demography

population dynamics

conservation biology

Author

Johan Jonasson

Chalmers, Mathematical Sciences, Analysis and Probability Theory

Tero Harkonen

Maritimas AB

L. Sundqvist

SMHI

Scott V. Edwards

Harvard University

Karin C. Harding

University of Gothenburg

American Naturalist

0003-0147 (ISSN) 1537-5323 (eISSN)

Vol. 200 1 48-62

Subject Categories

Evolutionary Biology

Biological Systematics

Probability Theory and Statistics

More information

Latest update

9/28/2022