Diversity of Femoral Diaphyseal Structure in East Asian Modern Humans During the Paleolithic-Neolithic Transition

During the Paleolithic-Neolithic transition, modern human femoral diaphyses underwent significant structural changes, primarily driven by shifts in subsistence patterns including decreased mobility and increased sedentism. However, femoral remains from East Asia during this period are inadequately reported and studied. This study investigates the femoral diaphyseal structures across East Asia during this transition, exploring their variation, evolutionary processes, and links to subsistence patterns reflected in the archeological record.

Human femora from Qihe Cave, Donghulin, and Taipinghu, representing South, North, and Northeast China during the transition, were analyzed. Midshaft cross-sectional shapes were compared with Early Upper Paleolithic (EUP), Late Upper Paleolithic (LUP), and recent sedentary agricultural (RSA) samples. Morphometric maps illustrating cortical bone thickness, external radius, and bending rigidity along the entire diaphysis were compared with Late Pleistocene early modern humans from South and North China and RSA specimens.

Analysis of midshaft cross-sectional shapes revealed that DHL 4 and Qihe M2 align with the LUP group, whereas DHL M1 and TPH 45 show close affinities with the RSA group. Statistical analyses based on morphometric maps further reveal that DHL 4 and Qihe M2 share key features with Late Pleistocene early modern humans, whereas DHL M1 and TPH 45 fall within the RSA variation range.

Two distinct femoral diaphyseal patterns are identified among East Asian modern humans during the transition, reflecting regional variations and intrapopulation divisions of labor, primarily associated with hunting and gathering strategies shaped by local environmental conditions and corresponding archeological cultures.