The ontogeny of Holocene and Late Pleistocene human postcranial strength.
While a wide variety of studies have focused on population variation in adult cross-sectional properties, relatively little is known about population variation in postcranial robusticity in immature individuals. Furthermore, the age at which the population differences readily detected in adults manifest during growth is also unknown. This research addresses these gaps in our current understanding through the analysis of immature humeral and femoral long bone strength. Cross-sectional geometry was used to compare the developmental trajectories of diaphyseal strength in Late Pleistocene Neandertal and modern human subadults to a sample of immature humans from seven geographically diverse Holocene populations. Population differences in size-standardized cross-sectional properties appear to be systemic and develop very early in ontogeny in the Holocene sample. In many cases, these differences are present before one year of age. In general, the Late Pleistocene fossil samples fit within the range of recent human variation in long bone strength. Population differences detected here are likely related to a combination of factors including activity patterns, genetic propensities, and nutritional status. These results highlight the complex mosaic of processes that result in adult postcranial robusticity, and suggest that further exploration of the developmental interplay between intrinsic and extrinsic influences on skeletal robusticity will likely enhance our understanding of adult postcranial morphology.
Cowgill
Libby W
LW
Department of Anthropology, University of Central Florida, Orlando, FL 32816-1361, USA. lcowgill@mail.ucf.edu
D000293:Adolescent; D000365:Age Determination by Skeleton; D000366:Age Determination by Teeth; D000818:Animals; D000885:Anthropology, Physical; D005075:Biological Evolution; D001696:Biomechanical Phenomena; D049628:Body Size; D015519:Bone Density; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D018483:Diaphyses / Q000254:growth & development; D005269:Femur / Q000033:anatomy & histology / Q000254:growth & development / Q000502:physiology*; D005580:Fossils; D015186:Hominidae / Q000033:anatomy & histology / Q000254:growth & development / Q000502:physiology; D006801:Humans; D006811:Humerus / Q000033:anatomy & histology / Q000254:growth & development / Q000502:physiology*; D007223:Infant; D011157:Population Dynamics