Center of body mass and the evolution of female body shape
Article first published online: 27 FEB 2003
Copyright © 2003 Wiley-Liss, Inc.
American Journal of Human Biology
Volume 15, Issue 2, pages 144–150, March/April 2003
How to Cite
Pawłowski, B. and Grabarczyk, M. (2003), Center of body mass and the evolution of female body shape. Am. J. Hum. Biol., 15: 144–150. doi: 10.1002/ajhb.10136
- Issue published online: 27 FEB 2003
- Article first published online: 27 FEB 2003
- Manuscript Accepted: 30 SEP 2002
- Manuscript Revised: 17 SEP 2002
- Manuscript Received: 26 MAR 2002
Among primates, the genus Homo has a unique sexual dimorphism in general body shape. The stenotypic female “hourglass figure” has often been attributed to sexual selection. Sexual dimorphism both in shape and in position of the center of body mass (CoM) emerges during puberty and is related to hormonal influences. These are only the proximal and not the ultimate causes of this feature. This article explores the hypothesis that the evolutionary (i.e., ultimate) reason for female body shape and male preference for a lower waist-to-hip ratio (WHR) is due to the acquisition of bipedal locomotion and different biomechanical constraints on each sex. The demands of pregnancy and subsequently carrying infants may have more tightly constrained CoM in females than in males. A lower-position of CoM relative to height (RCoM=(CoM/height)*100%) would contribute to better stability during pregnancy and infant carrying. Using body measurements from 119 female students, we show that RCoM correlates negatively with only maximal thigh circumference and positively with only WHR and shoulder width. The relationship between RCoM and traits that best characterize female body shape seems to confirm a hypothesis of biomechanical selection pressure that may have acted on Homo female morphology, thus contributing to sexual dimorphism. Am. J. Hum. Biol. 15:144–150, 2003. © 2003 Wiley-Liss, Inc.