Genetic diversity and inferred dispersal history of the Schlegel’s Japanese Gecko (Gekko japonicus) in Northeast Asia based on population genetic analyses and paleo-species distribution modelling (original) (raw)
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Heredity, 2003
Allozyme variation in two congeneric sympatric geckos, Gekko tawaensis and G. japonicus, from western Japan was examined. These species show similar densities and spatial arrangements of populations in this region, and their genetic structures are thus expected to have been formed under the influences of comparable geohistorical, environmental, and demographic factors. Results of the analyses, however, revealed strikingly different genetic patterns in the two species. Populations of G. tawaensis invariably showed a remarkably lowered heterozygosity (0-0.017) compared to G. japonicus (0.089-0.124). On the other hand, the genetic heterogeneity among populations is much greater in G. tawaensis (F ST ¼ 0.726) than in G. japonicus (F ST ¼ 0.101). The Mantel test failed to detect any significant correlations between log (estimated migration rate) and log (geographic distance) in either species, or between matrices of interpopulation pairwise F ST for the two species. These results suggest that, in each species, formation of the current genetic structure in western Japan has been chiefly influenced by stochastic factors, rather than the geohistorical architecture of this region. The high F ST and low heterozygosity in G. tawaensis suggest the effects of severe local fragmentation. On the other hand, the relatively low F ST and high heterozygosity in G. japonicus imply extensive gene flow among populations. Absence of significant correlations between the estimated migration rate and geographic distance in G. japonicus may suggest that such gene flow is promoted by human-mediated transport of this primarily house-dwelling lizard. Heredity (2003) 90, 90-97.
Frontiers in Ecology and Evolution, 2022
Seven species of house geckos occur across the scattered islands of the Indian Ocean. Two of these, Hemidactylus frenatus and H. parvimaculatus are both widespread and possess distribution profiles that suggest pre-European, or perhaps natural dispersal to some islands. Of these, only H. frenatus currently has sufficient molecular data to begin exploring dispersal patterns. This species is one of the most successful reptile colonists, as demonstrated by its global, pantropical distribution. While in some areas, such as Australia and continental South America, its dispersal patterns are both recent and well-known, early historical records of Hemidactylus in the Indian Ocean islands suggest earlier and/or potentially non-human-mediated dispersals. Here, we reviewed the historical literature and combined those reports with an assessment of mitochondrial DNA diversity of a global sampling of H. frenatus samples that included modern and museum specimens. Our results corroborate previous studies and demonstrate the relatively high diversity within this species' native range in Southeast Asia. In addition, the phylogenetic analysis suggests both a potential cryptic species complex, as well as global geographic structuring of different H. frenatus mitochondrial lineages. This has important implications for many comparative studies of this complex. Frequent and ongoing dispersals and colonizations complicate the identification of potentially older migration patterns. Further assessments including additional samples and analyses of additional genetic markers are necessary to disentangle older from more recent dispersals within this intriguing species.
Journal of Ecology and Environment, 2019
Background Studies of morphological variation within and among populations provide an opportunity to understand local adaptation and potential patterns of gene flow. To study the evolutionary divergence patterns of Schlegel’s Japanese gecko (Gekko japonicus) across its distribution, we analyzed data for 15 morphological characters of 324 individuals across 11 populations (2 in China, 4 in Japan, and 5 in Korea). Results Among-population morphological variation was smaller than within-population variation, which was primarily explained by variation in axilla-groin length, number of infralabials, number of scansors on toe IV, and head-related variables such as head height and width. The population discrimination power was 32.4% and in cluster analysis, populations from the three countries tended to intermix in two major groups. Conclusion Our results indicate that morphological differentiation among the studied populations is scarce, suggesting short history for some populations after...
Zootaxa, 2019
An integrative taxonomic analysis of the Ptychozoon lionotum group across its range in Indochina and Sundaland recovers P. lionotum sensu lato Annandale, 1905 as paraphyletic with respect to P. popaense Grismer, Wood, Thura, Grismer, Brown, & Stuart, 2018a and composed of four allopatric, genetically divergent, ND2 mitochondrial lineages. Multivariate and univariate analyses of continuous and discrete morphological and color pattern characters statistically and discretely diagnose each lineage from one another and together, with maximum likelihood and Bayesian inference analyses, provide the foundation for the recognition of each lineage as a new species—hypotheses corroborated with a Generalized Mixed Yule Coalescent species delimitation analysis. Ptychozoon cicakterbang sp. nov. ranges throughout Peninsular Malaysia to Pulau Natuna Besar, Indonesia; P. kabkaebin sp. nov. is endemic to northern and central Laos; and P. tokehos sp. nov. ranges from southern Thailand south of the Ist...
Conservation Genetics Resources, 2011
Thirteen tetranucleotide microsatellite loci were isolated from tetranucleotide microsatellite enriched libraries for the Tokay gecko (gekko gecko). The species is endemic to Southeast Asia, known to be a habitat specialist, and exposed to severe hunting pressures in the mountainous areas of Southeast Asia. These highly polymorphic markers (6-25 alleles) will facilitate the population genetic analyses of this species. In particular, they will enable estimates of gene flow between the two types of the Tokay gecko: the black-spotted Tokay gecko and the redspotted Tokay gecko-a critical element in assessing classification between the two.
With an impressively wide distribution, Gehyra mutilata is present on almost all Indian and Pacific Ocean islands and in large regions of Southeast Asia and Indonesia. Mitochondrial sequence data (~500 bp) from individuals covering large parts of its (mainly insular) distribution reveals deep cryptic variation and strong geographic structure, with two well differentiated lineages. Molecular data also reveals that the wide Indian and Pacific insular distribution of Gehyra is very recent and, at least across the Indian Ocean islands, most probably the result of human- aided dispersal, as no variation within this lineage was found. Further research is needed to determine geographic patterns of variation across Southeast Asia, the level of genetic variation, and possible mechanisms of speciation. If recognized as distinct taxa, the binomen Gehyra insulensis should be resurrected, and applied to the ‘Pacific lineage’.
Molecular Phylogenetics and Evolution, 2014
Recent studies of forest lizards in Southeast Asia have highlighted spectacular morphological and cryptic genetic diversity in several poorly known clades. Unfortunately, many of the included species have microhabitat preferences for forested environments, and therefore they are threatened by extensive forest destruction throughout the region. This is particularly true in the Philippines, an archipelago with a strikingly high proportion (84%) of endemic geckos. Abundances inferred from historical museum collections suggests that we are in a critical period where apparent declines in population viability and species' abundance have taken place faster than the growth in our understanding of alpha diversity. This phenomenon is exemplified in the exceedingly rare Philippine slender forest geckos of the genus Pseudogekko. Most of the known species are rarely encountered by field biologists, and species boundaries are unclear; this poor state of knowledge impedes effective conservation measures. Using the first multilocus phylogeny for these taxa, and phylogenetic and population genetic approaches, we elucidate evolutionary lineages and delimit species-level conservation targets in this unique radiation of endemic Philippine geckos. The results support the presence of widespread cryptic diversity in the genus, providing a framework for the re-evaluation of conservation priorities aimed at protecting these rare, forest-obligate species.
Genetic diversity and the history of pacific island house geckos (Hemidactylus and Lepidodactylus)
Biological Journal of The Linnean Society, 1993
Patterns of variation in chromosomes, mitochondrial DNA and allozymes were assessed for two parthenogenetic (Lepidodactylus lugubris and Hemidactylus garnotii) and one sexual (H. frenatus) species of house gecko that have colonized remote Pacific Ocean islands. The aims were to test the assumed recency of colonization and to provide information on the amount and distribution of genetic variation. Lepidodactylus lugubris was found to have diploid and triploid clones, high heterozygosity and moderate diversity for allozymes, and only two common types of mtDNA. The common clones distinguished by genetic analysis were geographically widespread. Together the genetic data suggest multiple origins of L. lugubris, with multiple recent invasions of the Pacific Ocean islands. Hemidactylus garnotii had low genetic diversity for chromosomes, mtDNA and allozymes. In contrast, its sexual congener, H. frenalus, had unusually high levels of mtDNA diversity, with some widespread variants. The low level of mtDNA diversity in the parthogenetic species provides strong support for the assumption that these are recent colonists of Pacific Islands.
Biological Journal of the Linnean Society, 2001
We assessed the validity of two gekkonid species, Gekko yakuensis and G. hkouensis, in southern Japan. We first assigned all 398 specimens into 18 samples merely on the basis of localities. By conducting significance test for deviations of genotype frequencies from Hardy-Weinberg at 11 allozyme loci, we checked the reproductive unity of constituents in each of those local samples, and where necessary, rearranged them into subsamples on the basis of genetic markers so that we recognized minimum reproductively cohesive units. We then compared allele frequencies among all samples and subsamples examined. Results clearly indicated that all but two can be classified into two groups that can be discriminated from each other by remarkable allele frequency differences at four diagnostic loci, and by large genetic distances even between sympatric subsamples. Observations of morphological features of the samples and subsamples confirmed that the two groups correspond to G. yakuensis and G. hokouensis, supporting validities of these two species. Allele frequency comparisons, however, also revealed that the remaining two samples, both from southern Kyushu, possessed 'marker alleles' of both G. yakuensis and G. hokouensis at all four diagnostic loci. These samples thus were considered to represent populations that have been derived through hybridization of the two species. Detailed analyses for genetic structures demonstrated that all hybrid genotypes in the two samples are post-F, generations with only one individual resulting from the back-cross with a pure line population of G. yakuensis. This finding negates the possibility that the hybrid populations are maintained by a constant supply of newly produced F1 hybrids, but suggests that the hybrid genotypes constitute stable breeding populations. This implies that the genealogical independence of G. yakuensis and G. hokouensis in several other sympatric areas has been maintained by operations of some isolation mechanisms at a pre-mating phase. Investigations of the morphological variation in each sample or subsample revealed that although the two species can be externally largely discriminated from each other by slight modifications of the currently used diagnoses, it is difficult t o detect their hybrids based solely on the morphological features.
Biological Journal of The Linnean Society, 2010
The influence of Pleistocene climatic oscillations on shaping the genetic structure of Asian biota is poorly known. The Japanese pipistrelle bat occurs over a wide range in eastern Asia, from Siberia to Japan. To test the relative impact of ancient and more recent events on genetic structure in this species, we combined mitochondrial (cytochrome b) and microsatellite markers to reconstruct its phylogeographic and demographic history on continental China and its offshore islands, Hainan Island and the Zhoushan Archipelago. Our mitochondrial DNA tree recovered two divergent geographical clades, indicating multiple glacial refugia in the region. The first clade was mainly confined to Hainan Island, indicating that gene flow between this population and the continent has been restricted, despite being repeatedly connected to the mainland during repeated glacial episodes. By contrast, haplotypes sampled on the Zhoushan Archipelago were mixed with those from the mainland, suggesting a recent shared history of expansion. Although microsatellite allele frequencies showed clear discontinuities across the sampling range, supporting the current isolation of both Hainan Island and the Zhoushan Archipelago, we also found clear evidence of more recent back colonization, probably via post-glacial expansion or, in the latter case, occasional long distance dispersal. The results obtained highlight the importance of using multiple sets of markers for teasing apart the roles of ancient and more recent events on population genetic structure. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 99, 582–594.