Phylogeography of the Endangered Lesser Antillean Iguana, Iguana Delicatissima: A Recent Diaspora in an Archipelago Known for Ancient Herpetological Endemism

Abstract

Iguana delicatissima is an endangered endemic of the Lesser Antilles in the Caribbean. Phylogeographic analyses for many terrestrial vertebrate species in the Caribbean, particularly lizards, suggest ancient divergence times. Often, the closest relatives of species are found on the same island, indicating that colonization rates are so low that speciation on islands is often more likely to generate biodiversity than subsequent colonization events. Mitochondrial sequence analysis of the region spanning ND4 was performed on I. delicatissima individuals from islands across the species' range to estimate genetic divergence among geographically isolated populations. Five unique haplotypes were recovered from 46 individuals. The majority of animals carry a single common haplotype. Two of the haplotypes were only present in individuals classified as hybrids from Îles des Saintes. The final 2 haplotypes, single nucleotide substitutions, were present in animals from Îlet Chancel of Martinique and Saint Barthélemy, respectively. Despite the great distances between islands and habitat heterogeneity within islands, this species is characterized by low haplotype diversity. The low mtDNA variation of I. delicatissima suggests a single colonization coupled with rapid range expansion, potentially hastened by human-mediated dispersal.

Age‐dependent, negative heterozygosity–fitness correlations and local effects in an endangered Caribbean reptile, Iguana delicatissima

“…for the Turks and Caicos iguana, and 7.3 in the Andros Island iguana (Colosimo, Knapp, Wallace, & Welch, 2014;Welch et al, 2011;Tzika et al 2008). While this level of genetic variation is low when con- (Martin et al, 2015). Hence, the lack of genetic variability in this population likely reflects a recent common ancestry and population expansion.…”

“…The relatively low levels of genetic variability in this species even extend to the mitochondrial genome. Haplotype variability at the mitochondrial ND4 locus across I. delicatissima 's range suggests that the species experienced a recent range expansion across the Lesser Antilles (Martin et al., 2015). Hence, the lack of genetic variability in this population likely reflects a recent common ancestry and population expansion.…”

Genetic structure at three spatial scales is consistent with limited philopatry in Ricord's Rock Iguanas (Cyclura ricordii)

“…The work by Colosimo et al () provides perhaps the most appropriate comparison to demonstrate how geographic barriers can restrict gene flow for Cyclura . A different pattern is known for Iguana delicatissima , present in the Lesser Antilles, where little genetic structure among their populations was detected (Martin, Knapp, Gerber, Thorpe, & Welch, ).…”

A story of nasal horns: A new species ofIguanaLaurenti, 1768 (Squamata, Iguanidae) in Saint Lucia, St Vincent & the Grenadines, and Grenada (Southern Lesser Antilles) and its implications for the taxonomy of the genusIguana

“…For ND4 analysis, we aligned our ND4 sequences from the 21 specimens sampled by the authors (Table 1) with Genbank sequences obtained from previous studies (Malone et al 2000; Malone & Davis 2004; Stephen et al 2013; Martin et al 2015). Phylogenetic trees were constructed using the Maximum Likelihood (ML) and Bayesian Inference (BI): The best-fit evolutionary model was calculated using the Bayesian Information Criterion in jModelTest2 (version 2.1.6; Darriba et al 2012) while the ML analysis was conducted in MEGA6 (Tamura et al 2013) based on the best-model obtained in jModeltest.…”