Effects of demographic stochasticity and life-history strategies on times and probabilities to fixation

Authored by Awad Diala Abu, Camille Coron

Date Published: 2018

DOI: 10.1038/s41437-018-0118-6

Sponsors: French National Research Agency (ANR) French National Center for Scientific Research (CNRS)

Platforms: C++

Model Documentation: Other Narrative Mathematical description

Model Code URLs: https://datadryad.org/stash/dataset/doi:10.5061/dryad.rm2jn70

Abstract

How life-history strategies influence the evolution of populations is not well understood. Most existing models stem from the Wright-Fisher model which considers discrete generations and a fixed population size, thus not taking into account any potential consequences of overlapping generations and demographic stochasticity on allelic frequencies. We introduce an individual-based model in which both population size and genotypic frequencies at a single bi-allelic locus are emergent properties of the model. Demographic parameters can be defined so as to represent a large range of r and K life-history strategies in a stable environment, and appropriate fixed effective population sizes are calculated so as to compare our model to the Wright-Fisher diffusion. Our results indicate that models with fixed population size that stem from the Wright-Fisher diffusion cannot fully capture the consequences of demographic stochasticity on allele fixation in long-lived species with low reproductive rates. This discrepancy is accentuated in the presence of demo-genetic feedback. Furthermore, we predict that populations with K life-histories should maintain lower genetic diversity than those with r life-histories.

Tags

Evolution Dynamics Genetic diversity selection environment diffusion Mutation Population-size Inbreeding depression Mutant-genes