The contributions of direct and indirect selection to the evolution of mating preferences

Servedio, Maria 1

Research facility: University of North Carolina at Chapel Hill

Published Nov 19, 2024 on Dryad. https://doi.org/10.5061/dryad.nvx0k6f25

Data files

Nov 19, 2024 version files 26.45 KB

Read_me.docx

24.01 KB
README.md

2.44 KB

Abstract

Many influential mathematical models of sexual selection have stressed that mating preferences evolve due to correlations that build between mating preferences and preferred display traits – that is, through indirect selection. Nevertheless, there is a perception that indirect selection should generally be overwhelmed by direct selection, for example in the form of search costs. Recent work by Fry has used quantitative genetic models to argue that in many cases, including when there are direct benefits (a fecundity advantage to mating with the preferred male), direct and indirect selection may be of similar magnitude. Here I use population genetic models, in which the strength of the genetic correlation is an emergent property of evolution at mating preference and display trait loci, to assess the relative contributions of direct and indirect selection to the evolution of mating preferences. For the cases of direct benefits and of indirect benefits with fixed and frequency-dependent search costs, I outline parameter values of fecundity benefits, preference strengths, and search costs for which indirect selection on female preferences can potentially predominate. I also analyze male mate choice under polygyny, showing that direct selection will always outweigh indirect selection except when there are direct benefits.

https://doi.org/10.5061/dryad.nvx0k6f25

Description of the data and file structure

The equations used for the project were derived in the Mathematica files and simulations were run in the C files.

Variables and parameters in files

int verticalres // vertical resolution of final table 1000

int horizontalres // horizontal resolution of final table 1000

double maxx // maximum value for x-axis variable on figures

double maxy // maximum value for y-axis variable

double intervalx // step size for x-axis variable

double intervaly // step size fot y-axis variable

double r // recombination rate

double alpha // preference strength

double f // fecundity advantage

double Diseq // linkage disequilibrium D

float dirsel // measure of direct selection

float indirsel // measure of indirect selection

double p2t1 // p2 in next generation

double t2t1 // t2 in next generation

double Diseqt1 // D in next generation.

double t2 // p2

double p2 // t2

double sp // selection on preference

double spmin // minimum value of sp for plots

double spexp // scaling factor to put sp on a log scale

float measure1 // measure of the association between the preference and trait in mated pairs

float p2atmax // p2 at the maximum value of D across starting frequencies

float t2atmax // t2 at the maximum value of D across starting frequencies

double t2val // starting values of t2 before iteration

double p2val // starting values of p2 before iteration

double cumdirsel // cumulative direct selection

double cumindirsel // cumulative indirect selection

int gen // current generation number

double prec // difference between successive generation values of the frequencies to use as a stopping criterion for the while loops

Code/software

The Mathematica files using Mathematica, or on Wolfram Cloud.