DOI: 10.5061/dryad.2d728
title: Data from: Covariation between human pelvis shape, stature, and head size alleviates the obstetric dilemma

description: Compared with other primates, childbirth is remarkably difficult in humans
 because the head of a human neonate is large relative to the
 birth-relevant dimensions of the maternal pelvis. It seems puzzling that
 females have not evolved wider pelvises despite the high maternal
 mortality and morbidity risk connected to childbirth. Despite this seeming
 lack of change in average pelvic morphology, we show that humans have
 evolved a complex link between pelvis shape, stature, and head
 circumference that was not recognized before. The identified covariance
 patterns contribute to ameliorate the “obstetric dilemma.” Females with a
 large head, who are likely to give birth to neonates with a large head,
 possess birth canals that are shaped to better accommodate large-headed
 neonates. Short females with an increased risk of cephalopelvic mismatch
 possess a rounder inlet, which is beneficial for obstetrics. We suggest
 that these covariances have evolved by the strong correlational selection
 resulting from childbirth. Although males are not subject to obstetric
 selection, they also show part of these association patterns, indicating a
 genetic–developmental origin of integration.
description: Human pelvis 3D landmark
 dataThis file contains
 fine-resolution 3D landmark data for 99 human pelvises (71 landmarks per
 pelvis, in columns) as well as information on stature and head
 circumference of these individuals (99 individuals, in rows). The data
 stem from a large dataset compiled by Herbert Reynolds and colleagues in
 1982 in a study for the Federal Aviation Administration, Washington DC,
 USA. Original publication: Reynolds HM, Snow CC, Young JW (1982) Spatial
 Geometry of the Human Pelvis. National Technical Information Service,
 Washington DC. Memorandum Report prepared for the U.S. Department of
 Transportation, Federal Aviation Administration, Office of Aviation
 Medicine. Their original aim was to develop a geometric model of human
 pelvic morphology to improve crash test devices and vehicle safety. The
 measured skeletons are part of the Hamann-Todd collection at the Cleveland
 Museum of Natural History, USA. Before skeletonization of the human
 bodies, a complete series of anthropometric measurements were taken. Of
 these measurements this file contains head circumference and stature. The
 study sample of Reynolds and colleagues was selected to match the body
 weight and size distribution of the US population. Only adult specimens,
 18-55 years old at time of death, were used. The pelvises were
 reassembled, and 3D landmark coordinates were recorded on each of the
 articulated pelvises using a Hewlett Packard digitizer. The first row of
 the data file contains variable names and landmark numbers. The first 5
 columns contain information on specimen number (1-99), ID (individual
 Hamann-Todd collection ID), sex (1=male, 2=female), head circumference (in
 mm) and stature (in mm). Landmark coordinates start in column 6.The 71 3D
 points per individual each consist of a x-, y- and z-coordinate, i.e. 71x3
 landmark coordinates. Axes scales are in mm. Missing data points are
 indicated as "X".fischer_mitteroecker_pelvisdata.csv