Dataset DOI: 10.5061/dryad.zs7h44jmm

Description of the data and file structure

Data collected to investigate genital divergence between two male morphs of the harvestman Poecilaemula lavarrei: larger, territory-holding Majors and smaller, sneaker Minors. It includes behavioral data such as female acceptance and copulation duration, as well as morphological data comprising linear, area, and shape measurements of genital structures.

Files and variables

File: Angle.csv

Description: This dataset contains angular measurements taken between males and females during copulation. Each row represents a measurement from a specimen identified by a unique code (Codigo) and categorized by male morph type (Morfo, either major - MA - or minor - MI). The dataset includes multiple repeated measurements per individual mate (ensuring measurement repeatability) under the column Medidas, with the corresponding measured angle recorded in Angulo.

File: copulasU.csv

Description: This dataset records copulation behavior in males of different morphs (Major vs. Minor). Each row represents a trial involving a male-female pair, identified by a female ID (id_f). The dataset includes the male morph type (Morfo), whether copulation occurred (copula, coded as Y/N), trial number (trial), and copulation duration (tempo) in MM:SS format. The data are used to model copulation probability and copulation duration across morphs and trials. This file has some cells intentionally left blank. We opted not to fill these cells with "NA" or other placeholder values to preserve the compatibility of the dataset with the R scripts provided, which expect purely numeric inputs in some columns. Modifying these would cause the scripts to return errors or invalid results. The empty cells are mainly due to cases where time variable do not apply — for instance, copulation duration is missing for mating trials in which no copulation occurred.

File: Genital_M1.csv

Description: The dataset contains linear measurements of genital structures from males of the harvestman Poecilaemula lavarrei, categorized into two male morphs: Major and Minor. The variables include: id (Male identifier), morfo (Male morph, either Major or Minor), trunk_len (Trunk length), glans_wid1 (Width of the pars basalis), glans_len (Length of the pars basalis), dorso (Dorsum width), placa_a_total (Area of the pars basalis), tapete_a_total (Area of the mat of microsetae). This file has some cells intentionally left blank. We opted not to fill these cells with "NA" or other placeholder values to preserve the compatibility of the dataset with the R scripts provided, which expect purely numeric inputs in some columns. Modifying these would cause the scripts to return errors or invalid results. The empty cells are mainly from cases of data that could not be collected due to technical limitations — for example, when genital structures were damaged (e.g., trunk broken) during specimen preparation, or when it was not possible to obtain usable images for measurements.

File: landmarks_drsl3.tps

Description: The dataset consists of 2D landmark configurations digitized from dorsal images of male specimens, formatted in a .tps file. Each specimen is identified using the specID = "ID" parameter.

File: landmarksVentral.tps

Description: The dataset consists of 2D landmark configurations digitized from ventral images of male specimens, formatted in a .tps file. Each specimen is identified using the specID = "ID" parameter. The landmarks include both fixed points and semi-landmarks, with their classification provided in a separate CSV file (curveslide.csv) used to define curve sliding during Generalized Procrustes Analysis (GPA).

File: curveslide.csv

Description: This file defines the sliding structure for landmarks used in geometric morphometric analyses. It specifies how individual landmarks should be allowed to "slide" during GPA. Each row corresponds to one sliding landmark and provides information on its neighboring landmarks. The column 'slide' is the ID of the landmark that will be allowed to slide, 'before' is the ID of the landmark immediately preceding the sliding landmark along the curve, and 'after', the ID of the landmark immediately following the sliding landmark along the curve.

Code/software

R Codes

linear_mesures.R - Performs allometric analysis on genital morphological traits across male morphs (Major and Minor) using SMA regression, descriptive statistics, and t-tests. Visualizations include log-log regression plots and boxplots for trunk length, glans width, and glans length relative to dorsum width.

area_measures.R - Performs statistical comparison of microsetae mat and ventral plate areas between male morphs (Major and Minor) using t-tests and descriptive statistics. Generates boxplots and log-log regression plots for absolute, proportional, and scaled area measures.

copula.R – Processes copulation data to analyze the effects of male morph (Major/Minor) and trial number on copulation occurrence and duration. Includes data cleaning, variable transformation, and fitting of mixed-effects models.

angle.R – Computes and compares mean angular measurements across male morphs (Major and Minor). Includes data cleaning, descriptive statistics (mean, SD, min, max, N), and a t-test to assess morph differences.

ventral_shape.R – Performs geometric morphometric analysis on ventral landmark data using Generalized Procrustes Analysis (GPA) with semi-landmarks. Includes Procrustes ANOVA to assess effects of centroid size and male morph type (Major vs. Minor) on shape variation.

dorsal_shape.R – Performs geometric morphometric analysis on dorsal landmark data using Generalized Procrustes Analysis (GPA). Includes Procrustes ANOVA to evaluate the effect of male morph type (Major vs. Minor) on shape, with and without centroid size (Csize) as a covariate.