DOI: 10.5061/dryad.5v04c22m
title: Data from: Sexual conflict and antagonistic coevolution across water strider populations

description: Microevolutionary studies have demonstrated sexually antagonistic
 selection on sexual traits, and existing evidence supports a
 macroevolutionary pattern of sexually antagonistic coevolution. Two
 current questions are how antagonistic selection within populations scales
 to divergence among populations, and to what extent intraspecific
 divergence matches species-level patterns. To address these questions, we
 conducted an intraspecific comparative study of sexual armaments and
 mating behaviours in a water strider (Gerris incognitus) in which male
 genitals grasp resistant females and female abdominal structures help ward
 off males. The degree of exaggeration of these armaments coevolves across
 species. We found a similar strong pattern of antagonistic coevolution
 among populations, suggesting that sexual conflict drives population
 differentiation in morphology. Furthermore, relative exaggeration in
 armaments was closely related to mating outcomes in a common environment.
 Interestingly, the effect of armaments on mating was mediated by
 population sexual size dimorphism. When females had a large size
 advantage, mating activity was low and independent of armaments, but when
 males had a relative size advantage, mating activity depended on which sex
 had relatively exaggerated armaments. Thus, a strong signal of sexually
 antagonistic coevolution is apparent even among populations. These results
 open opportunities to understand links between sexual arms races,
 ecological variation and reproductive isolation.
description: Data_archiving_population_morphologyThis file contains morphological data for 19 populations of water striders, Gerris incognitus, based on field collections. Male pregenital segment length and female spine height are given in millimeters for all 19 populations. The next 72 columns represent the data used in the two-block partial least squares analysis – the male and female reference specimens (a generalized least squares Procrustes superimposition) for 18 of the populations, generated from IMP CoordGen software (Sheets 2001, http://www3.canisius.edu/~sheets/morphsoft.html).Data_archiving_specimen_morphologyThis file contains morphological data for male and female specimens from each of 19 populations of water striders, Gerris incognitus, from field collections. Three measures of size are given for each specimen: body centroid size, body length, and the centroid size of the genital segments only. The next 32 columns contain the non-uniform and uniform shape variables for each specimen, generated from IMP CVAGen software (Sheets 2001, http://www3.canisius.edu/~sheets/morphsoft.html). PW refers to ‘partial warp’.Data_archiving_behaviourThis file contains data on mating behaviour for 18 populations of water striders, Gerris incognitus, from field collected individuals. Each data entry is a mean for a 1 h observation period of a bin of 6 male and 2 female water striders. The harassment index refers to the number of harassments from males experienced by each female per minute each female was available, i.e. not already engaged in an interaction with a male.Data_archiving_copulation_durationThis file contains data on copulation duration for 16 populations of water striders, Gerris incognitus, from field collected individuals. Data were collected from 3 h observations periods of a single male and female water strider within a pail.