DOI: 10.5061/dryad.mh1m9j4
title: Data from: The paradox of obligate sex: the roles of sexual conflict and mate scarcity in transitions to facultative and obligate asexuality

description: The maintenance of obligate sex in animals is a long-standing evolutionary
 paradox. To solve this puzzle, evolutionary models need to explain why
 obligately sexual populations consistently resist invasion by facultative
 strategies that combine the benefits of both sexual and asexual
 reproduction. Sexual antagonism and mate availability are thought to shape
 the occurrence of reproductive modes in facultative systems. But it is
 unclear how such factors interact with each other to influence facultative
 invasions and transitions to obligate asexuality. Using individual-based
 models, we clarify how sexually antagonistic coevolution and mate
 availability affect the likelihood that a mutant allele that gives virgin
 females the ability to reproduce parthenogenetically will invade an
 obligately sexual population. We show that male coercion cannot stop the
 allele from spreading because mutants generally benefit by producing at
 least some offspring asexually prior to encountering males. We find that
 effects of sexual conflict can lead to positive frequency-dependent
 dynamics, where the spread of the allele is promoted by effective
 (no-cost) resistance when males are common, and by mate limitation when
 sex-ratios are female-biased. However, once the mutant allele fixes,
 effective coercion prevents the complete loss of sex unless linkage
 disequilibrium can build up between the allele and alleles for effective
 resistance. Our findings clarify how limitations of female resistance
 imposed by the genetic architecture of sexual antagonism can promote the
 maintenance of sexual reproduction. At the same time, our finding of
 widespread obligate sex when costs of parthenogenesis are high suggests
 that developmental constraints could contribute to the rarity of
 facultative reproductive strategies in nature.
description: Reproductive mode
 outcomes from discrete-trait modelsThis data was obtained
 from simulations of the discrete-trait models (25 runs per parameter
 combination), showing the number of simulation runs ending in different
 reproductive mode outcomes. These data were used to create Figure 4 and
 Figure S1SINGLE_LOCUS_Reproductive_mode_outcomes_JEB.csvP allele outcomes from discrete-trait modelsThis data was obtained from simulations of the discrete-trait models (25 runs per parameter combination), showing the number of simulation runs ending in different P allele outcomes. These data were used to create Figure 4 and Figure S1SINGLE_LOCUS_P_allele_outcomes_JEB.csvReproductive mode outcomes from the continuous-trait modelThis data was obtained from simulations of the continuous-trait model (25 runs per parameter combination), showing the number of simulation runs ending in different reproductive mode outcomes. These data were used to create Figure S3.MULTI_LOCUS_Reproductive_mode_outcomes_JEB.csvP allele outcomes from the continuous-trait modelThis data was obtained from simulations of the continuous-trait model (25 runs per parameter combination), showing the number of simulation runs ending in different P allele outcomes. These data were used to create Figure S3.MULTI_LOCUS_P_allele_outcomes_JEB.csvParthenogenetic reproductive output from the discrete-trait resistance modelThis data was collected for 25 runs of the discrete-trait 'resistance' model. It shows the cumulative number of offspring produced parthenogenetically at certain timepoints for different female genotypes. This data was used to create Figure 2.data.collected.every.timestep.mendl.parth.reproductive.output_25_runs.csvParthenogenetic reproductive output BEFORE VS AFTER encounters from discrete-trait modelsThis data was collected for 25 runs for each of the discrete-trait models. It shows the cumulative number of offspring produced parthenogenetically before and after encounters with males at certain timepoints for different female genotypes. This data was used to create Figure 3.data.collected.every.timestep.mendl.epistasis.experiment_scarcity_VS_resistance_25_runs.csvNETLOGO code for discrete-trait model (high density setting)Use NetLogo version 5.2 to open and view this model. NetLogo can be downloaded for free from https://ccl.northwestern.edu/netlogo/oldversions.shtml. The experiment from which data were collected can be found in the Tools/BehaviorSpace drop-down menu once the file is open.HighENC.NETLOGO.mendl_additional.nlogoNETLOGO code for discrete-trait model (low density setting)Use NetLogo version 5.2 to open and view this model. NetLogo can be downloaded for free from https://ccl.northwestern.edu/netlogo/oldversions.shtml. The experiment from which data were collected can be found in the Tools/BehaviorSpace drop-down menu once the file is open.LowENC.NETLOGO.mendl_additional.nlogoNETLOGO code for continuous-trait model (low density setting)Use NetLogo version 5.2 to open and view this model. NetLogo can be downloaded for free from https://ccl.northwestern.edu/netlogo/oldversions.shtml. The experiment from which data were collected can be found in the Tools/BehaviorSpace drop-down menu once the file is open.LowENC.NETLOGO.infinit_additional.nlogoNETLOGO code for continuous-trait model (high density setting)Use NetLogo version 5.2 to open and view this model. NetLogo can be downloaded for free from https://ccl.northwestern.edu/netlogo/oldversions.shtml. The experiment from which data were collected can be found in the Tools/BehaviorSpace drop-down menu once the file is open.HighENC.NETLOGO.infinit_additional.nlogo