Correction: The Centipede Genus Scolopendra in Mainland Southeast Asia: Molecular Phylogenetics, Geometric Morphometrics and External Morphology as Tools for Species Delimitation.
Correction: The Centipede Genus Scolopendra in Mainland Southeast Asia: Molecular Phylogenetics, Geometric Morphometrics and External Morphology as Tools for Species Delimitation.
Project description:Seven Scolopendra species from the Southeast Asian mainland delimited based on standard external morphological characters represent monophyletic groups in phylogenetic trees inferred from concatenated sequences of three gene fragments (cytochrome c oxidase subunit 1, 16S rRNA and 28S rRNA) using Maximum likelihood and Bayesian inference. Geometric morphometric description of shape variation in the cephalic plate, forcipular coxosternite, and tergite of the ultimate leg-bearing segment provides additional criteria for distinguishing species. Colouration patterns in some Scolopendra species show a high degree of fit to phylogenetic trees at the population level. The most densely sampled species, Scolopendra dehaani Brandt, 1840, has three subclades with allopatric distributions in mainland SE Asia. The molecular phylogeny of S. pinguis Pocock, 1891, indicated ontogenetic colour variation among its populations. The taxonomic validation of S. dawydoffi Kronmüller, 2012, S. japonica Koch, 1878, and S. dehaani Brandt, 1840, each a former subspecies of S. subspinipes Leach, 1814 sensu Lewis, 2010, as full species was supported by molecular information and additional morphological data. Species delimitation in these taxonomically challenging animals is facilitated by an integrative approach that draws on both morphology and molecular phylogeny.
Project description:The centipede genus Scolopendra in mainland Southeast Asia is reviewed taxonomically based on morphological characters, informed by a molecular phylogenetic analysis using sequences from three mitochondrial and nuclear genes (COI, 16S rRNA and 28S rRNA). Eight nominal species of Scolopendra, namely Scolopendra morsitans Linnaeus, 1758, Scolopendra subspinipes Leach, 1816, Scolopendra dehaani Brandt, 1840, Scolopendra multidens Newport, 1844, Scolopendra calcarata Porat, 1876, Scolopendra japonica Koch, 1878, Scolopendra pinguis Pocock, 1891, and Scolopendra dawydoffi Kronmüller, 2012, are redescribed together with some revision of type materials. Geographical variation in each species has been compiled with reference to samples that span their distribution ranges in Southeast Asia and some parts of neighbouring areas such as East Asia, the Indian Ocean, and Africa. Comparative study of traditional taxonomic characters from external morphology provides further information to distinguish some closely related species. Scolopendra cataracta Siriwut, Edgecombe & Panha, sp. n., is described from the southern part of Laos, with additional records in Thailand and Vietnam. The phylogenetic framework for Southeast Asian Scolopendra recognizes Scolopendra calcarata + Scolopendra pinguis, Scolopendra morsitans, and a Scolopendra subspinipes group that unites the other six species as the main clades. Within the Scolopendra subspinipes group, two monophyletic groups can be distinguished by having either slender or short, thick ultimate leg prefemora and different numbers of apical spines on the coxopleuron. Scolopendra arborea Lewis, 1982, is placed in subjective synonymy with Scolopendra dehaani. A survey of external morphology of the genital segments confirms its potential for improving species identification in Scolopendra. Some observations on biology and behaviour are recorded based on field surveys in this area.
Project description:The taxonomy and geographic distributions of species of crab-eating frogs (Fejervarya cancrivora complex) in mainland Southeast Asia have been highly uncertain. Three taxonomic names are used in recent literature (F. cancrivora, F. raja, and F. moodiei) but the applications of these names to localities has been inconsistent, especially owing to the lack of available molecular data for F. raja. Morphometric and mitochondrial DNA variation was examined in these frogs, including name-bearing types and topotypes of all three species. Findings corroborate evidence for the existence of two species in coastal mainland Southeast Asia, with F. moodiei having a wide geographic distribution and F. cancrivora sensu stricto occurring only in extreme southern Thailand and peninsular Malaysia. Fejervarya raja is shown to be only a large-bodied population of F. cancrivora sensu stricto and is synonymized with that species. Revised descriptions of F. moodiei and F. cancrivora sensu stricto are provided.
Project description:The Cham people are the major Austronesian speakers of Mainland Southeast Asia (MSEA) and the reconstruction of the Cham population history can provide insights into their diffusion. In this study, we analyzed non-recombining region of the Y chromosome markers of 177 unrelated males from four populations in MSEA, including 59 Cham, 76 Kinh, 25 Lao, and 17 Thai individuals. Incorporating published data from mitochondrial DNA (mtDNA), our results indicated that, in general, the Chams are an indigenous Southeast Asian population. The origin of the Cham people involves the genetic admixture of the Austronesian immigrants from Island Southeast Asia (ISEA) with the local populations in MSEA. Discordance between the overall patterns of Y chromosome and mtDNA in the Chams is evidenced by the presence of some Y chromosome lineages that prevail in South Asians. Our results suggest that male-mediated dispersals via the spread of religions and business trade might play an important role in shaping the patrilineal gene pool of the Cham people.
Project description:Many species are defined in the Musa section within its natural diversification area in Southeast Asia. However, their actual number remains debated as botanical characterisation, distribution and intraspecific variability are still poorly known, compromising their preservation and their exploitation as crop wild relatives of cultivated forms. To address the underexplored Musa diversity in mainland Southeast Asia, at the northern edge of the natural range, 208 specimens were collected in Vietnam, Laos and China, mainly belonging to Musa balbisiana, M. itinerans, M. acuminata and M. yunnanensis. Data on location, morphology, environment and local knowledge were recorded, and leaf samples collected for high-throughput genotyping. This study combines geographical, morphological, and genomic diversity to clarify the taxonomic classification. The collected species exhibit highly distinctive morphologies and genomes, just as they differ in ranges and life traits. Intraspecific genomic diversity was also observed, although not necessarily morphologically perceptible. Mainland Southeast Asia is confirmed as a primary diversification centre for the Musa section. The diversity observed is only partially represented in major international ex situ collections, calling for their urgent enrichment and the promotion of in situ management procedures, for the protection of these threatened species and to better harness their potential in breeding programmes. Although considered wild, the species studied are all affected to varying extents by human use. Musa yunnanensis and M. acuminata subsp. burmannica are the most strictly wild forms, with spontaneous interspecific hybrids first described in this study. Although gathered as fodder, they were only occasionally dispersed outside their endemic zones. Musa itinerans is not cultivated per se, but natural populations are widely exploited, leading to a geographically structured diversity. The diversity of M. balbisiana is widely distributed and geographically structured by human activities. This species should be regarded as domesticated. These various stages, from simple opportunistic gathering to true domestication, shed light on the evolutionary history of today's cultivated varieties.
Project description:Affymetrix single nucleotide polymorphism (SNP) array data were collected to study genome-wide patterns of genomic variation across a broad geographical range of Island Southeast Asian populations. This region has experienced an extremely complex admixture history. Initially settled ~50,000 years ago, Island Southeast Asia has since been the recipient of multiple waves of population movements, most recently by Austronesian-speaking groups ultimately from Neolithic mainland Asia and later arrivals during the historic era from India and the Middle East. We have genotyped SNPs in ~500 individuals from 30 populations spanning this entire geographical region, from communities close to mainland Asia through to New Guinea. Particular attention has been paid to genomic data that are informative for population history, including the role of recent arrivals during the historic era and admixture with archaic hominins.
Project description:The centipede Scolopendra has important medicinal value and high toxicity, making it to be an interesting subject for evolutionary studies. However, species identification in China is difficult because of limited resource exploration and lack of recent taxonomic revision. To improve the identification and taxonomy of the genus Scolopendra in China, an in-depth investigation was conducted, and an integrated method that combined morphological characteristics with molecular data was applied. The identification key was revised to show the main difference among species. Our results indicated that morphologically-delimited species were consistent with the molecular analysis inferred from the COI sequences with genetic distances and phylogenetic trees. Additional morphometrics of four characteristics provided criteria for shape variation. These results suggested that the members of the genus Scolopendra in China could be delineated as 14 separate species. A new species from Lufeng county, Yunnan province, was proposed according to its characteristics, which was named as S. lufengia sp. nov. Our results comprehensively ascertained the taxonomic status of Scolopendra species in China, explored their phylogenetic relationships, showed a high success in the identification of medicinal centipedes.
Project description:A recent phylogenetic analysis of Triatoma pallidipennis, an important Chagas disease vector in Mexico, based on molecular markers, revealed five monophyletic haplogroups with validity as cryptic species. Here, we compare T. pallidipennis haplogroups using head and pronotum features, environmental characteristics of their habitats, and ecological niche modeling. To analyze variation in shape, images of the head and pronotum of the specimens were obtained and analyzed using methods based on landmarks and semi-landmarks. Ecological niche models were obtained from occurrence data, as well as a set of bioclimatic variables that characterized the environmental niche of each analyzed haplogroup. Deformation grids for head showed a slight displacement towards posterior region of pre-ocular landmarks. Greatest change in head shape was observed with strong displacement towards anterior region of antenniferous tubercle. Procrustes ANOVA and pairwise comparisons showed differences in mean head shape in almost all haplogroups. However, pairwise comparisons of mean pronotum shape only showed differences among three haplogroups. Correct classification of all haplogroups was not possible using discriminant analysis. Important differences were found among the environmental niches of the analyzed haplogroups. Ecological niche models of each haplogroup did not predict the climatic suitability areas of the other haplogroups, revealing differences in environmental conditions. Significant differences were found between at least two haplogroups, demonstrating distinct environmental preferences among them. Our results show how the analysis of morphometric variation and the characterization of the environmental conditions that define the climatic niche can be used to improve the delimitation of T. pallidipennis haplogroups that constitute cryptic species.