The interaction between selection, demography and selfing and how it affects population viability

PLoS One. 2014 Jan 21;9(1):e86125. doi: 10.1371/journal.pone.0086125. eCollection 2014.

Abstract

Population extinction due to the accumulation of deleterious mutations has only been considered to occur at small population sizes, large sexual populations being expected to efficiently purge these mutations. However, little is known about how the mutation load generated by segregating mutations affects population size and, eventually, population extinction. We propose a simple analytical model that takes into account both the demographic and genetic evolution of populations, linking population size, density dependence, the mutation load, and self-fertilisation. Analytical predictions were found to be relatively good predictors of population size and probability of population viability when verified using an explicit individual based stochastic model. We show that initially large populations do not always reach mutation-selection balance and can go extinct due to the accumulation of segregating deleterious mutations. Population survival depends not only on the relative fitness and demographic stochasticity, but also on the interaction between the two. When deleterious mutations are recessive, self-fertilisation affects viability non-monotonically and genomic cold-spots could favour the viability of outcrossing populations.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Evolution, Molecular
  • Extinction, Biological
  • Mutation
  • Population Dynamics
  • Selection, Genetic*
  • Self-Fertilization*
  • Time Factors

Grant support

This work benefited from the support of the Chair “Modélisation Mathémathique et Biodiversité” of Veolia Environnement - École Polytechnique - Muséum National d'Histoire Naturelle - Fondation X and the French Agence Nationale de la Recherche ANR-11-BSV7- 013-03. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.