2021 journal article

Internal structural properties of the humeral diaphyses in an early modern human from Tianyuan Cave, China

QUATERNARY INTERNATIONAL, 591, 107–118.

author keywords: Diaphyseal cortical thickness; Bone rigidity; Morphometric mapping; Upper limb; Late pleistocene; East asia
TL;DR: It is shown that upper limb internal structures can provide important information for inferring the behavior of ancient hominins, and the bilateral asymmetry of the right and left humeri may be more informative for discriminating between fossil and modern human samples than cortical thickness or rigidity values in only one side. (via Semantic Scholar)
UN Sustainable Development Goal Categories
13. Climate Action (Web of Science)
15. Life on Land (Web of Science)
Source: Web Of Science
Added: June 10, 2021

Since the cross-sectional geometries of long bone diaphyses preserve evidence of a bone's mechanical loading history, examination of a bones' cross-sectional properties can be used to inform its loading history. Here, we use a novel colormap method to quantitatively visualize the topography of cortical bone, second moment of areas, and polar moment of areas along the humeral diaphyses to shed light on the potential manipulative behaviors of the Tianyuan 1 fossil human (Homo sapiens). We compare both humeri of Tianyuan 1 to two Holocene Chinese populations. Our results show that the standardized cortical bone thickness, standardized second moment of areas, and standardized polar moment of areas of Tianyuan 1's right humeral diaphysis are greater than those of the left diaphysis. This evidence supports the hypothesis that the individual was right-handed. The greater medial and lateral cortical reinforcement in the right midshaft humerus, relative to that of the left humerus, may be related to increased unilateral physical activity of the right arm. Unlike the lower humeral asymmetry of recent human agriculturalists, the relatively higher bilateral asymmetry, combined with the relatively larger femoral robusticity, indicate that Tianyuan 1 lived an activity lifestyle compared to the agriculturalists investigated in this study. The bilateral asymmetry of the right and left humeri may be more informative for discriminating between fossil and recent modern human samples than cortical thickness or rigidity values in only one side. This study also indicates that upper limb internal structures can provide important information for inferring the behavior of ancient hominins.