Figure 3
Principal components plot of head shape variation. (A) Data for Plethodon jordani are emphasized, and (B) data for P. teyahalee are emphasized. The first two principal component axes explain 48.6% of the total variation in head shape. For each panel, individuals of the focal species are shown in large, gray symbols, the other species in light symbols. Also displayed are least-squares means for each population, and vectors of phenotypic evolution for each geographic transect. Geographic transects are shown as: Heintooga Ridge (solid lines and circles), Taywa Creek (dashed lines and squares), Kephart Prong (dotted lines and triangles). (C) Phenotypic evolution vectors for each transect for both species in this study. Phenotypic means for allopatric populations are shown in gray; phenotypic means for sympatric localities are shown in black. Thin-plate spline deformation grids depict typical head shapes for sympatric populations of P. jordani and P. teyahalee. A single deformation grid represents the allopatric populations for both species.