Fig. 1: Proximal femoral shape variance among Pan troglodytes, early hominin, and modern human groups.
From: Evolutionary roots of the risk of hip fracture in humans
a Principal component analysis (PCA) plot in shape-space for the proximal femur of Pan troglodytes (orange), Australopithecus/Paranthropus (light blue), early Homo (light green), Neanderthals (red), and recent humans (gray; age 18–45 years). PC1 (explains 24.4% of the shape variance) distinguishes between Pan troglodytes (N = 18) and recent humans (N = 74); early hominins (N = 4) and early Homo (N = 3) fell in between and can be distinguished from other groups along PC2 (explains 21.6% of the shape variance). Neanderthals are in the upper variation of recent humans along both PC1 and PC2. b PCA in shape-space for the proximal femur among populations with different subsistence strategies: Hunter-gatherers (N = 3) – Epi-Paleolithic (purple), early farmers (N = 5) – Pre-Pottery Neolithic (blue), pastoralists (N = 17) – Chalcolithic (pink), and recent humans (gray; 18–45 years old, N = 70). A gradient of change in the proximal femoral shape variance over time is evident along PC1. Details regarding the sample included in the study appear in Tables S1 and S2. c The positions of landmarks (orange, numbered dots), curves (green lines), and semi-landmarks (blue dots) on the proximal femora. d Definition of the landmarks’ position (definitions of the curves’ position are presented in Table 2).
