Figure 4: Results of a principal components analysis calculated with the variance and covariance estimates for 18 craniofacial traits for the Caribbean, SSI generalist-only, and SSI radiating populations.PC1 and PC2 explain 59% and 16% of the variance, respectively. Shapes and colors indicate the three focal groups (dark grey triangle: Caribbean group, light grey square: SSI generalist-only group, gold circle: SSI radiating group), and ellipses represent 95% confidence intervals per group. Arrows display four craniofacial traits that are most strongly correlated with PC1 (jaw closing in-lever and lower jaw length) and PC2 (maxillary head protrusion and nasal tissue protrusion). San Salvador Island generalist-only group clusters separately from the Caribbean and San Salvador Island radiating groups along PC1.