DOI: 10.5061/dryad.573n5tbnt
title: Data from: On the expression of male harm in <em>Drosophila melanogaster</em>: impacts of density and structural complexity of the mating environment

description: Male harm occurs when traits in males that increase their reproductive
 success incidentally reduce female fitness. In Drosophila melanogaster,
 many lab studies have revealed the presence of male harm, but recent work
 has shown that its expression can be dramatically reduced, even
 eliminated, when sexual interactions and mating occur in an environment
 that differs from traditional lab rearing vials. Here we follow up on this
 to separately test the effect of fly density and structural complexity of
 the mating environment in mediating the expression of male harm. We
 performed separate two-way factorial assays that measured the fitness of
 females while manipulating their exposure to males and the density of
 flies or the structural complexity of the environment during exposure.
 Male harm, quantified as the relative reduction in female fitness under
 increased male exposure, was not affected by density, but was
 significantly reduced –essentially eliminated– by increased structural
 complexity. Our results demonstrate that seemingly simple choices, like
 the environment used in a laboratory model system, can have profound
 impacts on the expression of harm and hence views on the prevalence of
 sexual conflict. This is noteworthy because conflict can shape other
 fundamental evolutionary processes including adaptation, purging, and
 speciation.
description: # Data from: On the expression of male harm in *Drosophila melanogaster*:
 impacts of density and structural complexity of the mating environment
 Dataset DOI:
 [10.5061/dryad.573n5tbnt](https://doi.org/10.5061/dryad.573n5tbnt) ##
 Description of the data and file structure Data and code for “On the
 expression of male harm in Drosophila melanogaster: impacts of density and
 structural complexity of the mating environment”, published by Osijo,
 Agrawal & Rundle in Evolution. Two experiments were performed, one
 manipulating the density of the mating environment and one manipulating
 the structural complexity of the mating environment. Data are provided for
 each as separate files, along with R code for analyzing both. Details of
 the methods are in published paper.  ### Files and variables #### File:
 density_exp_DRYAD_data.csv (called 'my_data1' in R code)
 **Description:** Data from the experiment that tested the effect of fly
 density on male-induced harm to females. The fitness of females was
 quantified in a two-way factorial experiment that manipulated their
 exposure to males (intermittent vs. continuous) and the number of flies
 (low vs. high density) during a four-day interaction period. NA values in
 row 77 denote missing data due to a technical error during the experiment.
 ##### Variables * Block: experimental block * Env: the density of flies in
 the mating environment: lowD = low density, highD = high density *
 ExpLevel: male exposure treatment: Low = intermittent exposure to males,
 High = continuous exposure to males * Container_ID: unique ID for each
 replicate container * Fem_surviving: number of females that survived the
 4-day interaction period (out of 15 for lowD, 60 for highD) *
 Fem_dying: number of females that died during the 4-day interaction period
 * total_offspring: total number of offspring produced by surviving females
 * offspring_per_surviving_female: total number of offspring divided by the
 number of surviving females * female_survival: number of females surviving
 divided by the total number of females (i.e. the sum of the number of
 females surviving and the number of females dying) * AvgNumOff: female
 fitness, estimated as offspring_per_surviving_female * female_survival
 #### File: R_code_DRYAD.R **Description:** R code for analyzing both data
 sets #### File: complexity_exp_DRYAD_data.csv (called 'my_data2'
 in R code) **Description:** Data from the experiment that tested the
 effect of the structural complexity of the mating environment on
 male-induced harm to females. The fitness of females was quantified in a
 two-way factorial experiment that manipulated their exposure to males
 (intermittent vs. continuous) and the structural complexity of the mating
 environment (simple vs. complex) during a four-day interaction period.
 ##### Variables * Block: experimental block * Env: the complexity of the
 mating environment: sim = simple, com = complex * ExpLevel: male exposure
 treatment: Low = intermittent exposure to males, High = continuous
 exposure to males * Container_ID: unique ID for each replicate container *
 Fem_surviving: number of females that survived the 4-day interaction
 period (out of 15) * Fem_dying: number of females that died during the
 4-day interaction period * total_offspring: total number of offspring
 produced by surviving females * offspring_per_surviving_female: total
 number of offspring divided by the number of surviving females *
 female_survival: number of females surviving divided by the total number
 of females (i.e.,15) * AvgNumOff: female fitness, estimated as
 offspring_per_surviving_female * female_survival ## Code/software R
 (v4.4.2) code for analyzing data. Packages: car Code is annotated.