Phylogeny and genetic differentiation
Both Microlophus and Phyllodactylus phylogenetic trees are similar in that (1) they support the monophyly of the two study species, (2) the individuals from Gardner, Champion and Floreana form three separate clades, respectively, and (3) Champion and Floreana clades are closely related (Fig. 2). The only exception to (2) and (3) is the only individual of M. grayii (AY625170) from Black Beach (Floreana), which is sister to the Champion clade. M. grayii is moderately supported (BS [bootstrap support] =62) as sister to a clade containing a paraphyletic M. albemarlensis (Isabela and Fernandina) and M. pacificus (Pinta). P. baurii is weakly (BS=40) supported as sister to a clade containing P. galapagensis(Santa Cruz), a paraphyletic P. maresi (Santiago), P. simpsoni (Isabela), and P. duncanensis (Pinzón).
Interspecific genetic distances (ND2) among species of the ‘Microlophus Western Radiation’ (Benavides et al., 2009) vary between 0.038–0.149 (average=0.094, SD=0.031), whereas intraspecific distances for M. grayii are 0.036 on average. Within M. grayii , the largest distances are between samples from Gardner and those from Floreana and Champion combined (0.068 on average). Similarly, interspecific genetic distances (ND4) among species of the ‘P. galapagensis Radiation’ (Torres-Carvajal et al., 2014) vary between 0.049–0.155 (average=0.108, SD=0.032), whereas intraspecific distances for P. baurii are 0.014 on average. Within P. baurii , the largest distances are between samples from Gardner and those from Floreana and Champion combined (0.026 on average).