DOI: 10.5061/dryad.brv15dvj8
title: How does robustness affect evolvability?

description: Here, by consolidating and extending simple models of how genetic
 robustness affects the evolvability of phenotypes with discrete states, I
 uncover three new insights. (i) Environmental robustness can boost
 evolvability by allowing populations to spread across a
 migrationally-neutral network of demes, and thereby increasing the
 diversity of plastic phenotypes that can be accessed by migration. (ii)
 Counter-intuitively, when adaptive landscapes are complex, an increase in
 environmental stability can increase the frequency of
 environmentally-robust but mutationally-sensitive genotypes. This is
 appears to be due to relaxed selection for mutational robustness in
 generalists. (iii) Evolvability can be affected by changes in mutational
 sensitivity, or by changes in the neighborhood of phenotypes accessible by
 non-neutral mutations. Because it allows for the evolution of increased
 evolvability without a concomitant increase in genetic load, selection
 should favor changes in the phenotypic neighborhood over changes in
 mutational sensitivity. Moreover, with fluctuating selection, the
 potential gains in evolvability conferred by increased mutational
 sensitivity can be diminished by selective sweeps on the phenotypic
 neighborhood.
description: This is an analysis of individual based, population genetic
 simulation models.
description: # How does robustness affect evolvability?
 [https://doi.org/10.5061/dryad.brv15dvj8](https://doi.org/10.5061/dryad.brv15dvj8) Codes for models of how mutational and environmental robustness affect evolvability. ## Code/Software Codes for models that explore the effect of mutational and environmental robustness on evolvability. File Hardy-2025-S1.R is an R implementation of the model of Meyers et al. 2005. The rest are Eidos codes of individual based model for the SLiM 4 framework (Haller and Messer 2023). Ancel Meyers, L., Ancel, F. D., & Lachmann, M. (2005). Evolution of genetic potential. PLoS computational biology, 1(3), e32. Haller, B. C., & Messer, P. W. (2023). SLiM 4: multispecies eco-evolutionary modeling. The American Naturalist, 201(5), E127-E139. ## Data All data were simulated by SLiM models and are in csv format. Hardy-2025-S3-simData.csv column names are **rep** (simulation replicate), **gen** (generation), **K** (phenotypic neighbrohood size), **q** (probability of neutral migration), **u** (mutation rate), **fA** (frequency of phenotype A), **fB** (frequency of phenotype B). Hardy_2025_S4_simData.csv columns names are **rep** (simulation replicate), **gen** (generation), **Regi** (selective regime, that is, the environmental state), **K**, (phenotypic neighborhood size), **mW** (mean fitness), **mQ** (mean probability of neutral mutation), **mB** (mean frequency of the B phenotype), **S** (richness of phenotypic neighborhoods), **D** (Simpson's diversity of phenotypic neighborhoods), **mV** (mean frequency of the generalist phenotype). Hardy_2025_S5_simData.csv column names are **rep** (simulation replicate), **gen** (generation), **lambda** (number of generations between environmental fluctuations), **rho** (ratio of genotype-phenotype-map mutations to genotype mutations), **mW** (mean fitness), **fV **(mean frequency of the generalist phenotype; called V in the manuscript), **fVk **(mean frequency at the which the generalist phenotype is in the phenotypic neighborhood), **mS** (mean phenotypic neighborhood richness), **tM** (the most common genotype-phenotype map), and **tg** (the most common genotype). Hardy_2025_S6_simData.csv column names are **rep** (simulation replicate), **gen** (generation), **Regi** (environmental state), **u** (mutation rate), **mW** (mean fitness), **mQ** (mean probability of neutral mutation), **mK** (mean phenotypic neighborhood size), **mB** (mean frequency of the B phenotype), m**S** (mean richness of phenotypic neghborhoods), m**D** (Simpson's diversity of phenotypic neighborhoods), **mV** (mean frequency of the generalist genotype), **mVk **(mean frequency of phenotypic neighborhoods containing the generalist phenotype).