Original Research Article
Lumbar ontogenetic growth and sexual dimorphism in modern humans
Version of Record online: 16 APR 2010
Copyright © 2010 Wiley-Liss, Inc.
American Journal of Human Biology
Volume 22, Issue 5, pages 596–603, September/October 2010
How to Cite
Valverde, E., Gálvez-López, E., Alba-Fernández, C., del Río, L. and Casinos, A. (2010), Lumbar ontogenetic growth and sexual dimorphism in modern humans. Am. J. Hum. Biol., 22: 596–603. doi: 10.1002/ajhb.21050
- Issue online: 19 AUG 2010
- Version of Record online: 16 APR 2010
- Manuscript Accepted: 31 JAN 2010
- Manuscript Revised: 21 JAN 2010
- Manuscript Received: 29 JUL 2009
- Ministerio de Educación y Ciencia, Spain. Grant Numbers: BOS2000-0997, CGL2005-04402/BOS
- AGAUR, Generalitat de Catalunya, Spain. Grant Number: 2005SGR00955
To detect and differentiate between possible heterochronic processes in the ontogenetic growth pattern of the human lumbar region, in relationship with sexual dimorphism. We measured the growth trajectories of average length and width, length/width ratio, posterior projected surface area, and bone mineral density using dual energy X-ray absorptiometry, in a sample group of 1718 modern humans. These growth patterns were analyzed using the Gompertz model. In adult lumbar region, only surface area and width were significantly higher in men. Regarding the ontogenetic growth pattern leading to the dimorphic states, all values obtained for women were significantly higher than those obtained for men. Maximum initial growth rates occurred for surface area and density in women. Width scaled faster than length in both sexes. The lumbar region followed patterns similar to those of other skeletal elements when compared with a previous classification of growth patterns in the human skeleton; however, in this study, the growth rate was slower. With regard to the effect of dimorphism, sexual differences in growth rate accounted for only a small proportion of the variation in lumbar length, mineral density, and surface area. Nevertheless, these sexual differences played an important role in the increase of the length/width ratio, which was reflected in the ages at which sexual dimorphism developed. The sexual dimorphism found in the lumbar region of human adults is not caused by any heterochronic process. The lower values of bone mineral density in adult women could explain the origin of some pathologies related. Am. J. Hum. Biol. 22:596–603, 2010. © 2010 Wiley-Liss, Inc.