Figure 2. (a) Principal component analysis (PCA) of onlyM. americana samples; (b) All examined New World Martessamples, identifying 2 intermediate hybrids; and (c) PCA of M. caurina samples only, demonstrating significant differentiation between insular and continental populations (39% of variation, PC1), and also between distinct continental populations of M. caurina (34% of variation, PC2). (d) mirrored mitochondrial genome (mitogenome, left) and autosomal SNP (right) phylogenies, depicting 2 monophyletic marten species (M. americana green, M. caurina blue) and 2 unsorted, putative hybrids (MTX, KUI). Sample abbreviations are defined in Table 1.