Systematics of the Anolis roquet Series of the Southern Lesser Antilles

Abstract

-We report a phylogenetic analysis of approximately 1330 bases of mitochondrial DNA sequence for eight species of the Anolis roquet series (Anolis aeneus, Anolis bonairensis, Anolis extremus, Anolis griseus, Anolis luciae, Anolis richardi, Anolis roquet, Anolis trinitatus). These data contain 410 characters that are parsimony informative for the A. roquet series plus three outgroup species. A parsimony analysis of these data, combined with previously published allozymic data, reveals a single most parsimonious tree with strong support for seven internal branches. Anolis bonairensis and A. luciae are sister taxa and together form a sister taxon to a group containing the other species. Relationships among A. griseus, A. trinitatus, and a clade containing the remaining species are unresolved. Within the latter clade, A. richardi is the sister taxon to a group containing A. aeneus, A. extremus, and A. roquet, with the latter two species being sister taxa. Reanalysis of previously published allozymic data produces no conflicts with the mtDNA tree for wellsupported branches. Parsimony analysis of the combined allozymic and DNA data gives a tree identical in topology to the tree resulting from the DNA analysis alone. In contrast to earlier studies, our phylogenetic analyses indicate that neither the small-bodied (A. aeneus, A. trinitatus) nor the large-bodied (A. griseus, A. richardi) species form monophyletic groups. The Anolis roquet series occupies the southern Lesser Antilles from Martinique to Grenada, including Barbados to the east, as well as two islands in the Venezuelan and Netherlands Antilles to the west (see Fig. 1; Underwood, 1959; Gorman and Dessauer, 1966; Gorman and Atkins, 1967, 1969; Gorman, 1968). Monophyly of this group is supported by allozymic and behavioral data (Gorman and Atkins, 1969). The A. roquet series is phylogenetically distinct from the Anolis bimaculatus species group occupying the northern Lesser Antilles (from Dominica northward), to which it appears not to be closely related (Etheridge, 1960; Gorman and Dessauer, 1966; Gorman and Atkins, 1969; Gorman et al., 1980; Guyer and Savage, 1986, 1992; Jackman et al., 1999). The Grenada and St. Vincent island banks each contain a pair of sympatric species, one large-bodied and the other considerably smaller. The other banks as well as the two western islands each contain single species intermediate in body size (Lazell, 1972; Schoener and Gorman, 1968; Roughgarden, 1995). The natural history of this group has been described by Gorman (1968), Schoener and Gorman (1968), Lazell (1972), and Gorman and Stamm (1975). 2 Corresponding Author. E-mail: creer@biology. wustl.edu Phylogenetic hypotheses for the A. roquet series have been proposed previously by Gorman and Atkins (1969) and Yang et al. (1974), based on karyotypic and allozymic data, and by Lazell (1972), based on morphology. Some immunological data have also been reported (Wyles and Gorman, 1980; Schochat and Dessauer, 1981). Roughgarden (1995) included the A. roquet series in a phylogenetic tree of the entire genus, in which he showed those relationships that appear well supported by the above works. Since the 1970s, many new techniques have been developed for systematic analysis, including statistical methods for assessing confidence in the results, both in terms of whole trees and individual branches. It is now possible to compare trees derived from different datasets in terms of branch support and test a variety of specific phylogenetic hypotheses in a statistically rigorous fashion. Most recently, Giannasi et al. (2000) have published trees derived from analysis of cytochrome b mitochondrial DNA sequence. Jackman et al. (1999) used sequences from the ND2 gene of the mitochondrial genome and adjacent regions to identify large-scale relationships among Anolis lizards. Based on their study, this particular region also appears suitable for analyzing relationships within various Anolis subclades. Here, we present mtDNA sequences from this region for species in the A. This content downloaded from 207.46.13.128 on Wed, 07 Sep 2016 06:32:03 UTC All use subject to http://about.jstor.org/terms SYSTEMATICS OF THE ANOLIS ROQUET SERIES