DOI: 10.5061/dryad.djh9w0w0h
title: Strong sexual selection fails to protect against inbreeding-driven extinction in a moth

description: Sexual selection is predicted to influence population persistence because
 skew in male reproductive success may facilitate the purging of mutation
 load. We manipulated the strength of sexual selection in populations of
 Indian meal moths, Plodia interpunctella, by biasing adult sex ratios to
 be either male- or female-biased, leading to strong and weak sexual
 selection in males, respectively. After between 19 and 22 generations of
 experimental evolution we examined whether mutation load differed between
 these populations by enforcing successive generations of inbreeding,
 tracking extinction events, offspring viability and assaying the effect of
 inbreeding on male mating success and female choice. We found no effect of
 the strength of sexual selection on the rate of extinction or offspring
 viability. We did, however, find changes in both male mating success and
 female choice, with both being influenced by the sex ratio treatment and
 the number of generations of inbreeding. Males from male-biased
 populations were more successful at mating with stock females, and mating
 success declined rapidly with inbreeding regardless of sex ratio
 treatment. Females from male-biased populations were less likely to mate
 with stock males at the onset of the experiment, but tended to mate more
 frequently with increasing inbreeding compared to females from
 female-biased populations. Our results demonstrate that while mating
 behaviours have diverged between male-biased and female-biased lines
 mutation loads remained similar. This suggests that the benefits of sexual
 selection to population fitness may be low or slow to accumulate under the
 benign environmental conditions in which these populations evolved.
description: All data were analysed using R studio and figures created using
 ggplot2   Description of column
 titles in data frame. <strong>Survival of inbred
 lines.csv: </strong> Block (Temp/Diet) =  block
 each population was established within Treatment
 (MB/FB) = sex ratio treatment, MB = males biased & FB = female
 biased Population = individual replicate population
 unique by block, treatment and number Family_ID =
 unique number assigned to each family
 Inbreeding_gen_extinction = the generation that the family became
 extinct (i.e. 0 = establishing families, 1 = 1 generation of full sib x
 sib inbreeding, etc) Reason_for_extinction =
 description at what stage the family was considered to be extinct during
 protocol <strong>Inbreeding egg to adult
 survival.csv:</strong> Generation = number of
 generations of full sib x sib inbreeding that egg to adult survival was
 assayed at (i.e. 0 = establishing families, 1 = 1 generation of full sib x
 sib inbreeding, etc) Block (Temp/Diet) =  block each
 population was established within Treatment (MB/FB) =
 sex ratio treatment, MB = males biased & FB = female
 biased Population = individual replicate population
 unique by block, treatment and number Family_ID =
 unique number assigned to each family eggs_transferred
 = number of eggs placed in 20 egg pot total_adults =
 number of individuals that survived to adult from the eggs
 transferred <strong>Mating
 assay.csv:</strong> Generation = number of
 generations of full sib x sib inbreeding that egg to adult survival was
 assayed at (i.e. 0 = establishing families, 1 = 1 generation of full sib x
 sib inbreeding, etc) Block (Temp/Diet) =  block each
 population was established within Treatment (MB/FB) =
 sex ratio treatment, MB = males biased & FB = female
 biased Population = individual replicate population
 unique by block, treatment and number Family_ID =
 unique number assigned to each family Focal = sex of
 focal individual i.e. from experimental family Mated =
 binary 1 or 0 if mating occurred, 1 = success, 0 = failure.