DOI: 10.5061/dryad.z8w9ghxqb
title: Covariance matrices supporting: An evolutionary quantitative genetic analysis of the impact of cephalopelvic disproportion on cranial and pelvic co-evolution in anthropoids

description: Evolutionary quantitative genetics methods are increasingly applied to
 studies of human skeletal evolution, with a growing emphasis on
 investigating postcranial evolution and the evolution of multiple skeletal
 elements. Here, we apply a commonly used method from evolutionary
 quantitative genetics, the drift-rate test, to test whether broad patterns
 of cranial and pelvic co-evolution within male, female, and pooled-sex
 samples of anthropoid primates follow those expected under the
 long-standing hypotheses of obstetric selection via cephalopelvic
 disproportion. Using interlandmark distances from the cranium and
 articulated pelvis from samples of four platyrrhine, four cercopithecoid,
 and five hominoid primate genera, we tested cranial, pelvic, and
 craniopelvic traits for evidence of deviation from neutral evolutionary
 patterns using both regression tests of within- on between-group
 eigenvalues and correlation tests of principal component scores. Results
 for analyses of shape data indicate that patterns of non-neutral evolution
 are different in male and female samples at multiple taxonomic levels, and
 that cranial and pelvic shape are co-evolving. Rejection of neutral
 evolution was pervasive for tests of form, but inconclusive regarding
 sex-specific selection or whether the cranium and pelvis appeared to
 covary or evolve independently. Sex-specific patterns of evolution support
 hypotheses that obstetric selection may have impacted multiple primate
 lineages. While size may play a role, it does not appear to be the
 dominant factor in evolution for either element. This study highlights the
 usefulness of using methods from evolutionary quantitative genetics to
 test long-standing hypotheses by incorporating multiple skeletal elements
 simultaneously.
description: Please see methods described in Cooper, M.J. and N. von
 Cramon-Taubadel (2025) An evolutionary quantitative genetic analysis of
 the impact of cephalopelvic disproportion on cranial and pelvic
 co-evolution in anthropoids, 188(1):e70109, American Journal of Biological
 Anthropology, doi: 10.1002/ajpa.70109
description: # Covariance matrices supporting: An evolutionary quantitative genetic
 analysis of the impact of cephalopelvic disproportion on cranial and
 pelvic co-evolution in anthropoids Dataset DOI:
 [10.5061/dryad.z8w9ghxqb](10.5061/dryad.z8w9ghxqb) ## Description of the
 data and file structure This dataset contains phenotypic
 variance/covariance matrices (V/CVs) derived from traits of the cranium
 and pelvis in thirteen primate genera: Alouatta, Aotus, Saimiri, Cebus,
 Trachypithecus, Macaca, Lophocebus, Chlorocebus, Hylobates, Pongo,
 Gorilla, Pan, and Homo. V/CV matrices are provided in .csv format. Two
 datasets were used: one containing form data (raw trait data) and one
 containing shape data (isometrically-scaled data). 3 V/CV matrices were
 constructed for each form and shape dataset, containing traits from the
 cranium, traits from the pelvis, and a combination of traits from the
 cranium and pelvis. Each set of matrices was constructed at the following
 taxonomic levels: 1) all anthropoid genera, 2) platyrrhines, 3)
 catarrhines, 4) cercopithecoids, and 5) hominoids. Additionally, V/CV
 matrices were calculated for females only, males only, and a dataset
 containing both males and females. A total of 90 .csv files are provided
 below, each containing one V/CV. For ease of downloading, V/CVs are
 separated into two .zip files, one containing all form data and one
 containing all shape data. .csv files are named with the taxonomic level
 and elements included. V/CVs derived from males or females only are noted
 with an M or F in the title, respectively. ### Files and variables ####
 File: Form_VCVs.zip **Description:** Variance-covariance matrices for form
 data (raw trait data). Contains V/CVs for cranial, pelvic, and combined
 cranial and pelvic traits for males, females, and pooled-sex samples at
 each of the five taxonomic levels noted above. #### File: Shape_VCVs.zip
 **Description:** Variance-covariance matrices for shape data
 (isometrically-scaled trait data) Contains V/CVs for cranial, pelvic, and
 combined cranial and pelvic traits for males, females, and pooled-sex
 samples at each of the five taxonomic levels noted above. ## Code/software
 V/CV matrices were calculated in R using base R code.