Figure 3

Principal component analysis of hemimandibular shape by population (using the set of nine landmarks): Natufian (green), Neolithic (blue), Chalcolithic (brown), Roman/Byzantine (light blue) and modern (gray). (a) The first two principal components (PCs) explain 39.2% of the variance. (b) The first and third PCs explain 34.1% of the variance . (c) Warped surfaces of the extreme values received for the first and third principal components (PC) using the set of 52 landmarks and semilandmarks (Supplementary Figure 1). Changes throughout the first PC, from the pre-agricultural population (the Natufian) to the post-industrial population (the Modern), appear in the mandibular body, which becomes more triangular (due to a reduction in the height of the posterior part of the mandibular body relative to the anterior part); the mandibular ramus, which becomes more narrow, elongated, and posteriorly tilted; the coronoid process, which becomes more narrow and elongated, extending beyond the condyle height; and the mandibular notch, which becomes narrower and deeper. Changes in shape throughout the third PC from post-Natufian (Neolithic, Chalcolithic, and Roman/Byzantine) to post-industrial populations exhibit an increase in chin projection, a narrowing of the coronoid, and a lengthening of the condyle. (d) Geometric morphometrics models used in the study: position of landmarks in the nine-landmark set marked with green dots. The position of landmarks in the fifty-two-landmark set marked with green and blue dots, and semilandmarks with yellow dots. Curves are marked with red lines.