Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 20
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
BMC Ecol Evol ; 24(1): 25, 2024 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-38378475

RESUMEN

BACKGROUND: Human-commensal species often display deep ancestral genetic structure within their native range and founder-effects and/or evidence of multiple introductions and admixture in newly established areas. We investigated the phylogeography of Eutropis multifasciata, an abundant human-commensal scincid lizard that occurs across Southeast Asia, to determine the extent of its native range and to assess the sources and signatures of human introduction outside of the native range. We sequenced over 350 samples of E. multifasciata for the mitochondrial ND2 gene and reanalyzed a previous RADseq population genetic dataset in a phylogenetic framework. RESULTS: Nuclear and mitochondrial trees are concordant and show that E. multifasciata has retained high levels of genetic structure across Southeast Asia despite being frequently moved by humans. Lineage boundaries in the native range roughly correspond to several major biogeographic barriers, including Wallace's Line and the Isthmus of Kra. Islands at the outer fringe of the range show evidence of founder-effects and multiple introductions. CONCLUSIONS: Most of enormous range of E. multifasciata across Southeast Asia is native and it only displays signs of human-introduction or recent expansion along the eastern and northern fringe of its range. There were at least three events of human-introductions to Taiwan and offshore islands, and several oceanic islands in eastern Indonesia show a similar pattern. In Myanmar and Hainan, there is a founder-effect consistent with post-warming expansion after the last glacial maxima or human introduction.


Asunto(s)
Lagartos , Animales , Humanos , Filogenia , Lagartos/genética , Asia Sudoriental , Filogeografía , Indonesia
2.
PeerJ ; 11: e15766, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37637176

RESUMEN

The Indonesian island of Sulawesi has a unique geology and geography, which have produced an astoundingly diverse and endemic flora and fauna and a fascinating biogeographic history. Much biodiversity research has focused on the regional endemism in the island's Central Core and on its four peninsulas, but the biodiversity of the island's many upland regions is still poorly understood for most taxa, including amphibians and reptiles. Here, we report the first of several planned full-mountain checklists from a series of herpetological surveys of Sulawesi's mountains conducted by our team. In more than 3 weeks of work on Gunung Galang, a 2,254 m peak west of the city of Tolitoli, Sulawesi Tengah Province, on Sulawesi's Northern Peninsula, we recovered nearly fifty species of reptiles and amphibians, more than a dozen of which are either new to science or known but undescribed. The incompleteness of our sampling suggests that many more species remain to be discovered on and around this mountain.


Asunto(s)
Biodiversidad , Lista de Verificación , Indonesia , Geografía , Geología
3.
Mol Phylogenet Evol ; 186: 107853, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37327831

RESUMEN

Bent-toed Geckos, genus Cyrtodactylus, are one of the most diverse terrestrial vertebrate groups, and their range extends from South Asia into Australo-Papua and adjacent Pacific islands. Given the generally high faunal endemism on Wallacean islands, it is rather paradoxical that the diversity in these geckos appears to be so low (21 species in Wallacea, 15 in the Philippines) compared with continental shelf assemblages (>300 species on Sunda + Sahul Shelves + adjacent islands). To determine whether this shortfall was real or an artifact of historical undersampling, we analyzed mitochondrial DNA sequences of hundreds of southern Wallacean samples (Lesser Sundas + southern Maluku). After screening to guide sample selection for target capture data collection, we obtained a 1150-locus genomic dataset (1,476,505 bp) for 119 samples of southern Wallacean and closely related lineages. The results suggest that species diversity of Cyrtodactylus in southern Wallacea is vastly underestimated, with phylogenomic and clustering analyses suggesting as many as 25 candidate species, in contrast to the 8 currently described. Gene exchange between adjacent candidate species is absent or minimal across the archipelago with only one case of > 0.5 migrants per generation. Biogeographical analysis suggests that the hitherto unrecognized diversity is the result of at least three independent dispersals from Sulawesi or its offshore islands into southern Wallacea between 6 and 14 Ma, with one invasion producing small-bodied geckos and the other two or three producing larger-bodied geckos. The smaller-bodied laevigatus group appears to be able to coexist with members of either larger-bodied clade, but we have yet to find members of the two larger-bodied clades occurring in sympatry, suggesting that ecological partitioning or competitive exclusion may be shaping individual island assemblages.


Asunto(s)
Escarabajos , Lagartos , Animales , Filogenia , Indonesia , Filipinas , Lagartos/genética
4.
BMC Genomics ; 24(1): 229, 2023 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-37131128

RESUMEN

BACKGROUND: Mitochondrial genome sequences have become critical to the study of biodiversity. Genome skimming and other short-read based methods are the most common approaches, but they are not well-suited to scale up to multiplexing hundreds of samples. Here, we report on a new approach to sequence hundreds to thousands of complete mitochondrial genomes in parallel using long-amplicon sequencing. We amplified the mitochondrial genome of 677 specimens in two partially overlapping amplicons and implemented an asymmetric PCR-based indexing approach to multiplex 1,159 long amplicons together on a single PacBio SMRT Sequel II cell. We also tested this method on Oxford Nanopore Technologies (ONT) MinION R9.4 to assess if this method could be applied to other long-read technologies. We implemented several optimizations that make this method significantly more efficient than alternative mitochondrial genome sequencing methods. RESULTS: With the PacBio sequencing data we recovered at least one of the two fragments for 96% of samples (~ 80-90%) with mean coverage ~ 1,500x. The ONT data recovered less than 50% of input fragments likely due to low throughput and the design of the Barcoded Universal Primers which were optimized for PacBio sequencing. We compared a single mitochondrial gene alignment to half and full mitochondrial genomes and found, as expected, increased tree support with longer alignments, though whole mitochondrial genomes were not significantly better than half mitochondrial genomes. CONCLUSIONS: This method can effectively capture thousands of long amplicons in a single run and be used to build more robust phylogenies quickly and effectively. We provide several recommendations for future users depending on the evolutionary scale of their system. A natural extension of this method is to collect multi-locus datasets consisting of mitochondrial genomes and several long nuclear loci at once.


Asunto(s)
Genoma Mitocondrial , Secuenciación de Nanoporos , Nanoporos , Análisis de Secuencia de ADN/métodos , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Biodiversidad
5.
Zootaxa ; 5150(4): 591-599, 2022 Jun 09.
Artículo en Inglés | MEDLINE | ID: mdl-36095645

RESUMEN

Frogs in the family Ranidae are diverse in Asia and are thought to have dispersed to the Sahul Shelf approximately 10 million years ago, where they radiated into more than a dozen species. Ranid species in the intervening oceanic islands of Wallacea, such as Hylarana florensis and H. elberti from the Lesser Sundas and H. moluccana from eastern Wallacea, are assumed to belong to the subgenus Papurana, yet this has not been confirmed with molecular data. We analyzed mitochondrial DNA of Hylarana species from five islands spanning the reported ranges of H. florensis and H. elberti and compared them to confirmed Papurana species and closely related subgenera within Hylarana. We find that the Lesser Sunda H. florensis and H. elberti form a clade that is sister to the rest of the Australo-Papuan Papurana assemblage. Species delimitation analyses and divergence time estimates suggest that populations of H. florensis on Lombok may be distinct from those on Flores at the species level. Likewise, populations of H. elberti on Sumba and Timor may be distinct from each other and from those on Wetar, tshe type locality of H. elberti. Samples from Babar Island thought to be members of H. elberti in fact belong to the wide-ranging H. daemeli, which occurs in northern Australia, across New Guinea, and on the neighboring island of Tanimbar. These results suggest that the Lesser Sundas may have served as a stepping-stone for colonization of the Sahul Shelf and that species diversity of Papurana frogs is underestimated in the Lesser Sundas.


Asunto(s)
ADN Mitocondrial , Ranidae , Animales , ADN Mitocondrial/genética , Filogenia , Ranidae/genética
6.
Evolution ; 76(10): 2281-2301, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35932243

RESUMEN

The archipelagos of Wallacea extend between the Sunda and Sahul Shelves, serving as a semipermeable two-way filter influencing faunal exchange between Asia and Australo-Papua. Forest skinks (Genus Sphenomorphus) are widespread throughout southern Wallacea and exhibit complex clinal, ontogenetic, sexual, and seasonal morphological variation, rendering species delimitation difficult. We screened a mitochondrial marker for 245 Sphenomorphus specimens from this area to inform the selection of 104 samples from which we used targeted sequence capture to generate a dataset of 1154 nuclear genes (∼1.8 Mb) plus complete mitochondrial genomes. Phylogenomic analyses recovered many deeply divergent lineages, three pairs of which are now sympatric, that began to diversify in the late Miocene shortly after the oldest islands are thought to have become emergent. We infer a complex and nonstepping-stone pattern of island colonization, with the group having originated in the Sunda Arc islands before using Sumba as a springboard for colonization of the Banda Arcs. Estimates of population structure and gene flow across the region suggest total isolation except between two Pleistocene Aggregate Island Complexes that become episodically land-bridged during glacial maxima. These historical processes have resulted in at least 11 Sphenomorphus species in the region, nine of which require formal description. This fine-scale geographic partitioning of undescribed species highlights the importance of utilizing comprehensive genomic studies for defining biodiversity hotspots to be considered for conservation protection.


Asunto(s)
Lagartos , Animales , Filogenia , Lagartos/genética , Flujo Génico , Genoma , Bosques , Filogeografía
7.
Biodivers Conserv ; 31(8-9): 2045-2062, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35633848

RESUMEN

Cryptic ecologies, the Wallacean Shortfall of undocumented species' geographical ranges and the Linnaean Shortfall of undescribed diversity, are all major barriers to conservation assessment. When these factors overlap with drivers of extinction risk, such as insular distributions, the number of threatened species in a region or clade may be underestimated, a situation we term 'cryptic extinction risk'. The genus Lepidodactylus is a diverse radiation of insular and arboreal geckos that occurs across the western Pacific. Previous work on Lepidodactylus showed evidence of evolutionary displacement around continental fringes, suggesting an inherent vulnerability to extinction from factors such as competition and predation. We sought to (1) comprehensively review status and threats, (2) estimate the number of undescribed species, and (3) estimate extinction risk in data deficient and candidate species, in Lepidodactylus. From our updated IUCN Red List assessment, 60% of the 58 recognized species are threatened (n = 15) or Data Deficient (n = 21), which is higher than reported for most other lizard groups. Species from the smaller and isolated Pacific islands are of greatest conservation concern, with most either threatened or Data Deficient, and all particularly vulnerable to invasive species. We estimated 32 undescribed candidate species and linear modelling predicted that an additional 18 species, among these and the data deficient species, are threatened with extinction. Focusing efforts to resolve the taxonomy and conservation status of key taxa, especially on small islands in the Pacific, is a high priority for conserving this remarkably diverse, yet poorly understood, lizard fauna. Our data highlight how cryptic ecologies and cryptic diversity combine and lead to significant underestimation of extinction risk. Supplementary Information: The online version contains supplementary material available at 10.1007/s10531-022-02412-x.

8.
Zootaxa ; 4999(1): 87-100, 2021 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-34810501

RESUMEN

The widespread parthenogenetic gecko Lepidodactylus lugubris is comprised of several clonal lineages, at least one of which has been known for some time to have originated from hybridization between its maternal ancestor, Lepidodactylus moestus, and a putatively undescribed paternal ancestor previously known only from remote islands in the Central Pacific. By integrating new genetic sequences from multiple studies on Lepidodactylus and incorporating new genetic sequences from previously sampled populations, we recovered a phylogenetic tree that shows a close genetic similarity between the generally hypothesized paternal hybrid ancestor and a recently described species from Maluku (Indonesia), Lepidodactylus pantai. Our results suggest that the paternal hybrid ancestor of at least one parthenogenetic clone of L. lugubris is conspecific with L. pantai and that the range of this species extends to Palau, the Caroline Islands, the Kei Islands, Wagabu, and potentially other small islands near New Guinea. Deeper genetic structure in the western (Palau, Maluku) versus eastern (eastern Melanesia, Micronesia, Polynesia) part of this species range suggests that the western populations likely dispersed via natural colonization, whereas the eastern populations may be the result of human-mediated dispersal. The potential taxonomic affinities and biogeographic history should be confirmed with further morphological and genetic analyses, including research on L. woodfordi from its type locality, which would have nomenclatural priority if found to be conspecific with L. pantai. We recommend referring to the wide-ranging sexual species as Lepidodactylus pantai until such a comparison can be made.


Asunto(s)
Lagartos , Animales , Hibridación Genética , Lagartos/genética , Partenogénesis , Filogenia
9.
Syst Biol ; 71(1): 221-241, 2021 12 16.
Artículo en Inglés | MEDLINE | ID: mdl-34117769

RESUMEN

The Lesser Sunda Archipelago offers exceptional potential as a model system for studying the dynamics of dispersal-driven diversification. The geographic proximity of the islands suggests the possibility for successful dispersal, but this is countered by the permanence of the marine barriers and extreme intervening currents that are expected to hinder gene flow. Phylogenetic and species delimitation analyses of flying lizards (genus Draco) using single mitochondrial genes, complete mitochondrial genomes, and exome-capture data sets identified 9-11 deeply divergent lineages including single-island endemics, lineages that span multiple islands, and parapatrically distributed nonsister lineages on the larger islands. Population clustering and PCA confirmed these genetic boundaries with isolation-by-distance playing a role in some islands or island sets. While gdi estimates place most candidate species comparisons in the ambiguous zone, migration estimates suggest 9 or 10 species exist with nuclear introgression detected across some intra-island contact zones. Initial entry of Draco into the archipelago occurred at 5.5-7.5 Ma, with most inter-island colonization events having occurred between 1-3 Ma. Biogeographical model testing favors scenarios integrating geographic distance and historical island connectivity, including an initial stepping-stone dispersal process from the Greater Sunda Shelf through the Sunda Arc as far eastward as Lembata Island. However, rather than reaching the adjacent island of Pantar by dispersing over the 15-km wide Alor Strait, Draco ultimately reached Pantar (and much of the rest of the archipelago) by way of a circuitous route involving at least five overwater dispersal events. These findings suggest that historical geological and oceanographic conditions heavily influenced dispersal pathways and gene flow, which in turn drove species formation and shaped species boundaries. [Biogeography; genomics, Indonesia; lizards; phylogeography; reptiles].


Asunto(s)
Flujo Génico , Lagartos , Animales , Indonesia , Lagartos/genética , Filogenia , Filogeografía
10.
Mol Phylogenet Evol ; 147: 106785, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32135306

RESUMEN

The gekkonid genus Cyrtodactylus is a highly diverse group of lizards (280 + species), which covers an expansive geographic range. Although this genus has been the focus of many taxonomic and molecular systematic studies, species on the Southeast Asian island of Borneo have remained understudied, leading to an unclear evolutionary history with cascading effects on taxonomy and biogeographic inferences. We assembled the most comprehensive multilocus Bornean dataset (one mitochondrial and three nuclear loci) that included 129 novel sequences and representatives from each known Cyrtodactylus species on the island to validate taxonomic status, assess species diversity, and elucidate biogeographic patterns. Our results uncovered a high proportion of cryptic diversity and revealed numerous taxonomic complications, especially within the C. consobrinus, C. malayanus, and C. pubisulcus groups. Comparisons of pairwise genetic distances and a preliminary species delimitation analysis using the Automatic Barcode Gap Discovery (ABGD) method demonstrated that some wide-ranging species on Borneo likely comprise multiple distinct and deeply divergent lineages, each with more restricted distributional ranges. We also tested the prevailing biogeographic hypothesis of a single invasion from Borneo into the Philippines. Our analyses revealed that Philippine taxa were not monophyletic, but were likely derived from multiple separate invasions into the geopolitical areas comprising the Philippines. Although our investigation of Bornean Cyrtodactylus is the most comprehensive to-date, it highlights the need for expanded taxonomic sampling and suggests that our knowledge of the evolutionary history, systematics, and biogeography of Bornean Cyrtodactylus is far from complete.


Asunto(s)
Biodiversidad , Sitios Genéticos , Lagartos/clasificación , Lagartos/genética , Filogenia , Filogeografía , Animales , Teorema de Bayes , Borneo , Calibración , Núcleo Celular/genética , Código de Barras del ADN Taxonómico , Islas , Modelos Genéticos , Filipinas , Especificidad de la Especie , Factores de Tiempo
11.
Mol Biol Evol ; 37(3): 904-922, 2020 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-31710677

RESUMEN

Marker selection has emerged as an important component of phylogenomic study design due to rising concerns of the effects of gene tree estimation error, model misspecification, and data-type differences. Researchers must balance various trade-offs associated with locus length and evolutionary rate among other factors. The most commonly used reduced representation data sets for phylogenomics are ultraconserved elements (UCEs) and Anchored Hybrid Enrichment (AHE). Here, we introduce Rapidly Evolving Long Exon Capture (RELEC), a new set of loci that targets single exons that are both rapidly evolving (evolutionary rate faster than RAG1) and relatively long in length (>1,500 bp), while at the same time avoiding paralogy issues across amniotes. We compare the RELEC data set to UCEs and AHE in squamate reptiles by aligning and analyzing orthologous sequences from 17 squamate genomes, composed of 10 snakes and 7 lizards. The RELEC data set (179 loci) outperforms AHE and UCEs by maximizing per-locus genetic variation while maintaining presence and orthology across a range of evolutionary scales. RELEC markers show higher phylogenetic informativeness than UCE and AHE loci, and RELEC gene trees show greater similarity to the species tree than AHE or UCE gene trees. Furthermore, with fewer loci, RELEC remains computationally tractable for full Bayesian coalescent species tree analyses. We contrast RELEC to and discuss important aspects of comparable methods, and demonstrate how RELEC may be the most effective set of loci for resolving difficult nodes and rapid radiations. We provide several resources for capturing or extracting RELEC loci from other amniote groups.


Asunto(s)
Biología Computacional/métodos , Reptiles/genética , Secuenciación Completa del Genoma/métodos , Animales , Teorema de Bayes , Evolución Molecular , Exones , Sitios Genéticos , Filogenia , Reptiles/clasificación , Alineación de Secuencia
12.
Zootaxa ; 4609(2): zootaxa.4609.2.10, 2019 May 23.
Artículo en Inglés | MEDLINE | ID: mdl-31717113

RESUMEN

An integrative taxonomic analysis of Subdoluseps herberti from southern Thailand and Peninsular Malaysia and S. samajaya from Sarawak, East Malaysia (Borneo) recovers the former as paraphyletic with respect to the latter. The analyses recover the three southernmost populations of S. herberti in Peninsular Malaysia as conspecific and the sister lineage of S. samajaya, whereas S. herberti from Thailand and northern Peninsular Malaysia constitute the sister species to S. samajaya plus the southern three Peninsular Malaysian populations. As such, the southern populations are described herein as S. malayana sp. nov. and all three species are referred to as the S. herberti group. Clade boundaries and breaks within this group on the Thai-Malay Peninsula occurring at the Isthmus of Kra, across the Kangar-Pattani line, and between the Thai-Malay Peninsula and Borneo are consistent with phylogeographic patterns of other Sundaic taxa. The discovery of S. malayana sp. nov. continues to underscore the fact that, despite the well-studied nature of the lizard fauna of Peninsular Malaysia, much of it still remains unrealized and for conservation efforts to move forward, field research followed by expeditiously revised taxonomies must continue.


Asunto(s)
Lagartos , Animales , Borneo , Malasia , Filogenia , Tailandia
13.
Proc Biol Sci ; 286(1904): 20182575, 2019 06 12.
Artículo en Inglés | MEDLINE | ID: mdl-31161911

RESUMEN

The importance of long-distance dispersal (LDD) in shaping geographical distributions has been debated since the nineteenth century. In terrestrial vertebrates, LDD events across large water bodies are considered highly improbable, but organismal traits affecting dispersal capacity are generally not taken into account. Here, we focus on a recent lizard radiation and combine a summary-coalescent species tree based on 1225 exons with a probabilistic model that links dispersal capacity to an evolving trait, to investigate whether ecological specialization has influenced the probability of trans-oceanic dispersal. Cryptoblepharus species that occur in coastal habitats have on average dispersed 13 to 14 times more frequently than non-coastal species and coastal specialization has, therefore, led to an extraordinarily widespread distribution that includes multiple continents and distant island archipelagoes. Furthermore, their presence across the Pacific substantially predates the age of human colonization and we can explicitly reject the possibility that these patterns are solely shaped by human-mediated dispersal. Overall, by combining new analytical methods with a comprehensive phylogenomic dataset, we use a quantitative framework to show how coastal specialization can influence dispersal capacity and eventually shape geographical distributions at a macroevolutionary scale.


Asunto(s)
Distribución Animal , Lagartos/fisiología , Animales , Evolución Biológica , Ecosistema , Lagartos/clasificación , Lagartos/genética , Océanos y Mares , Filogenia , Filogeografía , Dinámica Poblacional
14.
Zootaxa ; 4370(4): 345-362, 2018 Jan 12.
Artículo en Inglés | MEDLINE | ID: mdl-29689833

RESUMEN

We collected two specimens of an undescribed species of Lygosoma from pitfall traps in an urban rainforest in Kuching and from the base of a forested hill in western Sarawak, East Malaysia. The new species is diagnosable from all south-east Asian congeners by morphological characters, and most closely resembles Lygosoma herberti from the Thai-Malay Peninsula. The new species shows substantial molecular divergence from its closest relatives in two protein-coding genes, one mitochondrial (ND1) and one nuclear (R35) that we sequenced for several south-east Asian congeners. We describe the new species on the basis of this distinct morphology and genetic divergence. It is the third species of Lygosoma known from Borneo, and highlights the continuing rise in lizard species diversity on the island. In addition, the discovery of this species from a small urban rainforest underscores the importance of preserving intact rainforest areas of any size in maintaining species diversity.


Asunto(s)
Lagartos , Animales , Borneo , Malasia , Filogenia , Bosque Lluvioso
15.
Zootaxa ; 4350(1): 91-105, 2017 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-29245567

RESUMEN

Lepidodactylus pantai is a new species of gecko from the Kei Islands, Maluku, Indonesia that is closely associated with intertidal habitats. This species does not fit cleanly into any of the three species groups described for the genus because it possesses the unique combination of both divided terminal scansors on all toes and a nearly completely cylindrical tail without fringes or evidence of dorsoventral compression. A phylogenetic analysis including this species demonstrates that it is the sister taxon of a population from Palau, and that this clade is sister to the clade containing Group III species for which we have molecular data.


Asunto(s)
Lagartos , Distribución Animal , Estructuras Animales , Animales , Tamaño Corporal , Indonesia , Islas , Palau , Filogenia
16.
PeerJ ; 5: e3762, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29093993

RESUMEN

Episodic sea level changes that repeatedly exposed and inundated the Sunda Shelf characterize the Pleistocene. Available evidence points to a more xeric central Sunda Shelf during periods of low sea levels, and despite the broad land connections that persisted during this time, some organisms are assumed to have faced barriers to dispersal between land-masses on the Sunda Shelf. Eutropis rugifera is a secretive, forest adapted scincid lizard that ranges across the Sunda Shelf. In this study, we sequenced one mitochondrial (ND2) and four nuclear (BRCA1, BRCA2, RAG1, and MC1R) markers and generated a time-calibrated phylogeny in BEAST to test whether divergence times between Sundaic populations of E. rugifera occurred during Pleistocene sea-level changes, or if they predate the Pleistocene. We find that E. rugifera shows pre-Pleistocene divergences between populations on different Sundaic land-masses. The earliest divergence within E. rugifera separates the Philippine samples from the Sundaic samples approximately 16 Ma; the Philippine populations thus cannot be considered conspecific with Sundaic congeners. Sundaic populations diverged approximately 6 Ma, and populations within Borneo from Sabah and Sarawak separated approximately 4.5 Ma in the early Pliocene, followed by further cladogenesis in Sarawak through the Pleistocene. Divergence of peninsular Malaysian populations from the Mentawai Archipelago occurred approximately 5 Ma. Separation among island populations from the Mentawai Archipelago likely dates to the Pliocene/Pleistocene boundary approximately 3.5 Ma, and our samples from peninsular Malaysia appear to coalesce in the middle Pleistocene, about 1 Ma. Coupled with the monophyly of these populations, these divergence times suggest that despite consistent land-connections between these regions throughout the Pleistocene E. rugifera still faced barriers to dispersal, which may be a result of environmental shifts that accompanied the sea-level changes.

17.
Zootaxa ; 4258(6): 539-550, 2017 05 03.
Artículo en Inglés | MEDLINE | ID: mdl-28609896

RESUMEN

A new species of the genus Tropidophorus is described from Putai, upper Baleh, Kapit districts, Sarawak, East Malaysia (Borneo). Tropidophorus sebi sp. nov. is diagnosable from congeners from Borneo by the combination of the following characters: head shields present, dorsal and lateral scales smooth; parietal scales in two pairs; supraciliaries eight; supraoculars four; supralabials seven; infralabials four; postmental undivided; longitudinal scale rows 58; ventrals 53; transverse scale rows at midbody 34; subcaudals 98; preanals enlarged, single; and subdigital lamellae of Toe IV 19. In addition, we determine the phylogenetic position of this species within the Tropidophorus group based on mitochondrial markers, and present a key to identification of the known Bornean species in the genus.


Asunto(s)
Peces , Distribución Animal , Estructuras Animales , Animales , Tamaño Corporal , Borneo , Malasia , Tamaño de los Órganos , Filogenia
18.
Biol Lett ; 12(8)2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-27555650

RESUMEN

Most mammals and approximately 20% of squamates (lizards and snakes) are viviparous, whereas all crocodilians, birds and turtles are oviparous. Viviparity evolved greater than 100 times in squamates, including multiple times in Mabuyinae (Reptilia: Scincidae), making this group ideal for studying the evolution of nutritional patterns associated with viviparity. Previous studies suggest that extreme matrotrophy, the support of virtually all of embryonic development by maternal nutrients, evolved as many as three times in Mabuyinae: in Neotropical Mabuyinae (63 species), Eumecia (2 species; Africa) and Trachylepis ivensii (Africa). However, no explicit phylogenetic hypotheses exist for understanding the evolution of extreme matrotrophy. Using multilocus DNA data, we inferred a species tree for Mabuyinae that implies that T. ivensii (here assigned to the resurrected genus Lubuya) is sister to Eumecia, suggesting that extreme matrotrophy evolved only once in African mabuyine skinks.


Asunto(s)
Lagartos , Animales , Filogenia , Serpientes , Tortugas
19.
Zootaxa ; 4093(3): 407-23, 2016 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-27394504

RESUMEN

We describe two new species of skinks from Gunung Penrissen, Sarawak, Malaysia, in northern Borneo, Tytthoscincus batupanggah sp. nov. and T. leproauricularis sp. nov. Morphological and molecular analyses both corroborate the two new species as unique compared to all other Tytthoscincus and additional Sphenomorphus that are candidates for taxonomic placement in the genus Tytthoscincus. Despite their phenotypic similarity and sympatric distribution, a molecular analysis shows that the new species are not sister taxa and exhibit a deep genetic divergence between each of their respective sister taxa. We discuss how historical climatic and geographic processes may have led to the co-distribution of two relatively distantly related phenotypically similar species. In light of these discoveries, we also emphasize the importance of conserving primary montane tropical rainforest for maintaining species diversity.


Asunto(s)
Lagartos/clasificación , Distribución Animal , Estructuras Animales/anatomía & histología , Estructuras Animales/crecimiento & desarrollo , Animales , Tamaño Corporal , Ecosistema , Femenino , Flujo Genético , Lagartos/anatomía & histología , Lagartos/crecimiento & desarrollo , Malasia , Masculino , Tamaño de los Órganos , Filogenia
20.
Mol Phylogenet Evol ; 102: 220-32, 2016 09.
Artículo en Inglés | MEDLINE | ID: mdl-27246101

RESUMEN

Despite an abundance of phylogenetic studies focused on intrageneric relationships of members of the Mabuya group, the intergeneric relationships have remained difficult to resolve. The most-persistent unresolved regions of the phylogeny of the group include: (1) the placement of the Middle-Eastern Trachylepis with respect to the Afro-Malagasy Trachylepis and its taxonomic status; (2) the phylogenetic position of the Cape Verdean Chioninia within the larger Mabuya group; (3) support for the placement of Dasia with respect to the entire group; and (4) the phylogenetic placement of Eutropis novemcarinata with respect to other Eutropis and Dasia. In this study, we include representatives of all these taxa as well as African Eumecia and Neotropical Mabuya. We seek to address these phylogenetic and systematic issues by generating a well-resolved and supported phylogeny for the Mabuya group as a whole that can be used to develop a stable taxonomy and reconstruct the geographic patterns of diversification within the group. To meet these goals, we built a large multi-locus dataset of 11 markers (nine nuclear and two mitochondrial), and performed concatenated and species tree analyses to generate a well-supported phylogeny for the group. Statistical topology tests reject the monophyly of Middle-Eastern Trachylepis with Afro-Malagasy Trachylepis, and to reflect monophyly we place the Middle-Eastern species into a previously described genus, Heremites. Cape-Verdean Chioninia are resolved as the strongly supported sister-group to Afro-Malagasy Trachylepis. Monophyly of the Southeast-Asian genera, Eutropis and Dasia, is not supported, with a clade composed of Dasia+Eutropis novemcarinata more closely related to the rest of the Mabuya group than to the remaining Eutropis. The phylogenetic position of E. novemcarinata renders Eutropis polyphyletic, and we therefore describe and place E. novemcarinata into a new monotypic genus, Toenayar, to preserve monophyly among the genera. In light of these novel findings, we review and discuss the historical biogeography of the entire Mabuya group.


Asunto(s)
Lagartos/clasificación , Animales , Proteína BRCA1/química , Proteína BRCA1/genética , Proteína BRCA1/metabolismo , Proteína BRCA2/química , Proteína BRCA2/genética , Proteína BRCA2/metabolismo , ADN/química , ADN/aislamiento & purificación , ADN/metabolismo , ADN Mitocondrial/química , ADN Mitocondrial/aislamiento & purificación , ADN Mitocondrial/metabolismo , Lagartos/genética , NADH Deshidrogenasa/química , NADH Deshidrogenasa/genética , NADH Deshidrogenasa/metabolismo , Filogenia , Filogeografía , ARN Ribosómico 16S/química , ARN Ribosómico 16S/genética , ARN Ribosómico 16S/metabolismo , Análisis de Secuencia de ADN
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...