Epigenetic mutations can both help and hinder adaptive evolution
Authored by Sinead Collins, Ilkka Kronholm
Date Published: 2016
DOI: 10.1111/mec.13296
Sponsors:
Academy of Finland
Royal Society
European Research Council (ERC)
Platforms:
R
Model Documentation:
Other Narrative
Mathematical description
Model Code URLs:
Model code not found
Abstract
Epigenetic variation is being integrated into our understanding of
adaptation, yet we lack models on how epigenetic mutations affect
evolution that includes de novo genetic change. We model the effects of
epigenetic mutations on the dynamics and endpoints of adaptive walks-a
process where a series of beneficial mutations move a population towards
a fitness optimum. We use an individual-based model of an asexual
population, where mutational effects are drawn from Fisher's geometric
model. We find cases where epigenetic mutations speed adaptation or
result in populations with higher fitness. However, we also find cases
where they slow adaptation or result in populations with lower fitness.
The effect of epigenetic mutations on adaptive walks depends crucially
on their stability and fitness effects relative to genetic mutations, with small-effect epigenetic mutations generally speeding adaptation, and epigenetic mutations with the same fitness effects as genetic
mutations slowing adaptation. Our work reveals a complex relationship
between epigenetic mutations and natural selection and highlights the
need for empirical data.
Tags
Adaptation
Dynamics
phenotypic plasticity
Inheritance
Model
Divergence
Beneficial mutations
Asexual populations
Genetic assimilation
Methylation variants