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A likelihood framework analysis of an island radiation: phylogeography of the Lesser Antillean gecko S phaerodactylus vincenti , in comparison with the anole A nolis roquet
Author(s) -
SurgetGroba Yann,
Thorpe Roger S.
Publication year - 2013
Publication title -
journal of biogeography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.7
H-Index - 158
eISSN - 1365-2699
pISSN - 0305-0270
DOI - 10.1111/j.1365-2699.2012.02778.x
Subject(s) - phylogeography , allopatric speciation , maximum parsimony , biology , phylogenetic tree , species complex , clade , evolutionary biology , cytochrome b , zoology , genetics , population , gene , demography , sociology
Aim The W est I ndies have hosted several spectacular radiations, including that of the litter geckos of the genus S phaerodactylus . We analyse the phylogeography of the S phaerodactylus vincenti complex and explore the possibility that there may be cryptic species to be revealed. Postulated colonization routes in this complex are estimated and compared with those of co‐distributed lizards (the A nolis roquet complex). Location Lesser Antilles. Methods Phylogenetic relationships (gene trees) were estimated using maximum parsimony and Bayesian analysis of the cytochrome b sequence [mitochondrial DNA (mt DNA )] obtained from 53 individuals sampled in D ominica, M artinique, S t V incent, B equia and M ustique. The B ayesian relaxed‐clock method was used to estimate the time to the most recent common ancestor and a likelihood framework analysis was employed to probabilistically estimate the geographic origin of the main clades of the S . vincenti complex. These methods were repeated on the co‐distributed species complex of A . roquet , and their timing and colonization routes were compared. Results Phylogenetic analysis of mt DNA of the S . vincenti complex in the L esser A ntilles reveals a deep split between the northern (north M artinique and D ominica) and southern (south M artinique, S t V incent, G renadines and possibly S t L ucia) clades with about 22% mean divergence. Together with geological information, these results suggest that Martinique is occupied by populations that began evolving in allopatry 12.5 million years ago, and which came into secondary contact once precursor islands coalesced to produce present‐day Martinique. Main conclusions We regard the two main forms of S phaerodactylus as separate species based on their substantial mt DNA divergence and largely diagnostic scapula ocelli (present in the north, but largely absent in the south). Although there are similarities in the precursor islands occupied by the A nolis and S phaerodactylus species, their colonization sequence is different, probably due to the stochastic nature of the long‐distance dispersal involved in island colonization.