DOI: 10.5061/dryad.79cnp5j4r
title: Data from: Are weapon allometries steeper in major or minor males? A meta-analysis

description: Competition for mates can drive the evolution of exaggerated weaponry and
 male dimorphism associated with alternative reproductive tactics. In
 terrestrial arthropods, male dimorphism is often detected as non-linear
 allometries, where the scaling relationship between weapon size and body
 size differs in intercept and/or slope between morphs. Understanding the
 patterns of non-linear allometries is important as it can provide insights
 into threshold evolution and the strength of selection experienced by each
 morph. Numerous studies in male-dimorphic arthropods have reported that
 allometric slopes of weapons are shallower in large “major” males compared
 to small “minor” males. Because this pattern is common among beetles that
 undergo complete metamorphosis (holometabolous), researchers have
 hypothesized that the slope change reflects resource depletion during
 pupal development. However, no comprehensive survey has examined the
 generality of this trend. We systematically searched the literature for
 reports of weapon allometries in male dimorphic species and conducted a
 phylogenetically controlled meta-analysis to explore the factors
 influencing the difference in slopes between morphs. Our search identified
 59 effect sizes from 19 studies, 50 species, and 5 orders of terrestrial
 arthropods. We found strong evidence that metamorphosis type influences
 the patterns of weapon allometries. Slopes were significantly steeper in
 minor males compared to major males in holometabolous species, but there
 was no difference in slopes between morphs in hemimetabolous species
 (i.e., those that undergo incomplete or no metamorphosis). These results
 support the hypothesis that holometabolous species face a resource ceiling
 during pupal development that limits the exaggeration of weapon size.
description: # Are weapon allometries steeper in major or minor males? A meta-analysis
 The dataset contains two Excel files and 2 R files.  ## Data Contents:
 meta_data.csv is the complete dataset used in the meta-regression analyses
 meta_code.R includes all R code used for the meta-regression analyses and
 production of figures Compiling_data.xlsx reports the raw data extracted
 from each study used to calculate effect sizes (Hedges' g)
 Calculating Hedges g.R reports the R code used for calculating effect
 sizes based on the compiled data ## Key to datasets: ### The
 meta\_data.csv file has the following columns: **Citation:** Author and
 year of the study included in the meta-analysis **Metamorphosis:**
 Categorial variable indicating the type of metamorphosis of the study
 organism (holometabolous = complete metamorphosis; hemimetabolous =
 incomplete or no metamorphosis) **Order:** Taxonomic rank of the study
 organism **Family:** Taxonomic rank of the study organism **rotl_spp:**
 Species name of the study organism, as written in the Open Tree of Life
 (OTL) database. If the original species was not included in the OTL
 database, a substitution was found from the same genus or family.
 **Species:** Species name of the study organism, as written in the paper.
 **Weapon:** Type of weapon measured **g:** Hedges’ *g*, a standardized
 measure of effect size **Lower CI:** Lower 95% confidence interval of
 Hedges’ g value **Upper CI:** Upper 95% confidence interval of Hedges’ g
 value **var.g:** variance of Hedges’ g **log_Major_Weapon:** log average
 weapon size of major males in study organism, used to calculate index of
 weapon exaggeration **log_Major_Body:** log average body size of major
 males in study organism, used to calculate index of weapon exaggeration
 **Has_weapon:** Categorial variable (Y or N) indicating whether the study
 organism has weapon size data and could be included in the analysis on
 weapon exaggeration **Year:** Publication year of study included in the
 analysis **Breakpoint:** Statistical method used by the study authors to
 separate male morphs (Body = body size breakpoint; Weapon = weapon size
 breakpoint; Ratio = breakpoint identified by inspecting frequency
 histogram of weapon to body size ratios; Mixture = morphs separated using
 cluster analysis or finite mixture models). **Study:** Identifier for each
 unique study **Observation:** Identifier for each unique observation ###
 The Compiling\_data.xlsx file has multiple pages with the following
 columns: **Citation:** Author and year of the study included in the
 meta-analysis **Species:** Species name of the study organism, as written
 in the paper. **Weapon:** Type of weapon measured **Minor/Major:** Male
 morph for reported allometric data **Mean:** Average allometric slope for
 the given morph and species **Lower CI:** Lower 95% confidence interval of
 estimated allometric slope for the given morph and species **Upper CI:**
 Upper 95% confidence interval of estimated allometric slope for the given
 morph and species **N:** Sample size of the given morph and species
 **SD:** Standard deviation of estimated allometric slope for the given
 morph and species **SE:** Standard error of estimated allometric slope for
 the given morph and species