Population genetics of Galápagos land iguana (genus Conolophus) remnant populations

Abstract

The Jamaican boa (Epicrates subflavus; also called Yellow boa) is an endemic species whose natural populations greatly and constantly declined since the late 19th century, mainly because of predation by introduced species, human persecution, and habitat destruction. In-situ conservation of the Jamaican boa is seriously hindered by the lack of information on demographic and ecological parameters as well as by a poor understanding of the population structure and species distribution in the wild. Here, using nine nuclear microsatellite loci and a fragment of the mitochondrial cytochrome b gene from 87 wild-born individuals, we present the first molecular genetic analyses focusing on the diversity and structure of the natural populations of the Jamaican boa. A model-based clustering analysis of multilocus microsatellite genotypes identifies three groups that are also significantly differentiated on the basis of F-statistics. Similarly, haplotypic network reconstruction methods applied on the cytochrome b haplotypes isolated here identify two well-differentiated haplogroups separated by four to six fixed mutations. Bayesian and metaGA analyses of the mitochondrial data set combined with sequences from other Boidae species indicate that rooting of the haplotypic network occurs most likely between the two defined haplogroups. Both analyses (based on nuclear and mitochondrial markers) underline an Eastern vs. (Western + Central) pattern of differentiation in agreement with geological data and patterns of differentiation uncovered in other vertebrate and invertebrate Jamaican species. Our results provide important insights for improving management of ex-situ captive populations and for guiding the development of proper in-situ species survival and habitat management plans for this spectacular, yet poorly known and vulnerable, snake.

An overlooked pink species of land iguana in the Galápagos

“…A similar magnitude of microsatellite differentiation was observed among C. subcristatus populations from other islands (12). Although the 2 forms still share 26% of alleles, none of the rosada individuals investigated incorporated genes from the syntopic yellow iguanas, at least in the past 2 generations, and only 1 yellow individual shows possible mixed ancestry with a rosada grandparent.…”

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

“…This average is low compared to other iguana species; the average number of alleles per locus was 6 in a study of the Galápagos land iguana, 3.5 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 contrasted with that of other iguana species, it appears to be consistent with the findings from other studies of I. delicatissima (average 1.6 alleles per locus, Valette et al.…”

Genetic variation in three paddlefish (Polyodon spathula Walbaum) stocks based on microsatellite DNA analysis

“…Values about 0.7 or less suggest that a population has gone through a recent reduction in size. Low M values ranging from 0.29 to 0.43 across a population are specific for remnant populations (for example the Galapagos iguana) and indicate significant reduction of the population size in the past (Tzika et al, 2008). M values of the Garza-Williamson index, ranging from 0.68 to 0.77, were lower in Polish and Ukrainian stocks than that estimated for the Mississippi population (0.80).…”