High species diversity of Phintella and Phintella-like spiders (Araneae: Salticidae) in Vietnam revealed by DNA-based species delimitation analyses.

Salticidae (jumping spiders) usually exhibit pronounced sexual dimorphism in adult morphology, particularly body coloration and size and shape of the first legs. Consequently, the male and female from the same species might be erroneously assigned to different species or even different genera, which could generate synonymies in classification if only morphological data were used. Phintella is a species-rich genus of Salticidae, which currently exhibits 76 named species. However, the male-female counterpart is unknown for nearly half of the species. In this study, we used a molecular approach to delineate the species boundaries for Phintella and Phintella-like specimens collected in Vietnam, using morphological information as supporting data. We used three gene fragments (mitochondrial COI, 16S-ND1, and nuclear 28S) and biogeographical considerations for species delimitation. A total of 22 putative species were recognized: 18 species of the genus Phintella, one species of the genus Lechia (L. squamata), and three species of the genus Phinteloides. Eleven undescribed species were discovered, of which seven have a male-female combination, two species have only males, and two species have only females. The crown age of Phintella was estimated at the Serravallian stage of the Miocene after the increase of species number around 16 MYA. The crown ages of most putative species recognized in this study were estimated in the Pleistocene, and the divergence among sister species likely occurred from the mid-Miocene to the Pliocene. Our ancestral range reconstruction results showed that the diversification of our ingroup was governed by progressive dispersal events, i.e., Phintella and their related species in Vietnam diversified while expanding their range on the continent. Our results provide fundamental biodiversity data for a high-diversity genus in Vietnamese Phintella spiders.

Deciphering molecular basis of pesticide-induced recurrent pregnancy loss: insights from transcriptomics analysis.

Recent studies have revealed a notable connection between pesticide exposure and Recurrent Pregnancy Loss (RPL), yet the precise molecular underpinning of this toxicity remains elusive. Through the alignment of Differentially Expressed Genes (DEGs) of healthy and RPL patients with the target genes of 9 pesticide components, we identified a set of 12 genes responsible for RPL etiology. Interestingly, biological process showed that besides RPL, those 12 genes also associated with preeclampsia and cardiovascular disease. Enrichment analysis showed the engagement of these genes associated with essential roles in the molecular transport of small molecules, as well as the aldosterone-regulated sodium reabsorption, endocrine and other factor-regulated calcium reabsorption, mineral absorption, ion homeostasis, and ion transport by P-type ATPases. Notably, the crosstalk targets between pesticide components played crucial roles in influencing RPL results, suggesting a role in attenuating pesticide agents that contribute to RPL. It is important to note that non-significant concentration of the pesticide components observed in both control and RPL samples should not prematurely undermine the potential for pesticides to induce RPL in humans. This study emphasizes the complexity of pesticide induced RPL and highlights avenues for further research and precautionary measures.

Epidemiology-based wastewater monitoring for ecological risks of anti-tuberculosis drugs mixture effects.

First-line anti-tuberculosis (TB) drugs are commonly used to treat TB worldwide, leading to more contaminated wastewater being widely discharged into aquatic environments. However, studies of mixture interactions of anti-TB drugs and their residues in aquatic environments are scarce. This study aimed to determine the toxic interactions of anti-TB drugs-isoniazid (INH), rifampicin (RMP), and ethambutol (EMB)-in binary and ternary mixtures on Daphnia magna and used the epidemiology of TB history to construct epidemiology-based wastewater monitoring for assessing the environmental release of residues and related ecological risks. The acute immobilization of median effect concentrations (EC50) was 25.6 mg L-1 for INH, 80.9 mg L-1 for RMP, and 188.8 mg L-1 for EMB, as toxic units (TUs) for assessing mixture toxicity. The ternary mixture exhibited the lowest TUs at 50 % effects with 1.12, followed by 1.28 for RMP + EMB, 1.54 for INH + RMP, and 1.93 for INH + EMB, indicating antagonistic interactions. Nevertheless, the combination index (CBI) was used to examine the mixture toxicity in response to immobilization, revealing that the ternary mixture of CBI ranged from 1.01 to 1.08, tending to have a nearly additive effect when suffering >50 % effect (at high concentration levels). The forecasted environmentally relevant concentrations of anti-TB drugs have been on downward trends with ng L-1 level from 2020 to 2030 in Kaohsiung, Taiwan. Although ecotoxicological risks from the wastewater treatment plant and receiving water in the field were slightly greater than the prediction from epidemiology-based wastewater monitoring, there were no risk concerns. Here, we achieved the establishment of evidence that anti-TB drug mixtures' interaction and epidemiological-based monitoring support a systematic approach, resolving the absence of the mixture toxicity information for anti-TB mixture risk assessment in aquatic environments.

Northward geographic diversification of a kleptoparasitic spider Argyrodes lanyuensis (Araneae, Theridiidae) from the Philippine Archipelago to Orchid Island.

Oceanic islands are unique geographic systems that promote local adaptations and allopatric speciation in many of their highly endemic taxa. This is a common case in the Philippine Archipelago, where numerous unrelated taxa on islands have been inferred to have diversified in isolation. However, few cases have been reported in invertebrates especially among parasitic organisms. Here, we tested for biogeographical structure in novel populations of the "generalist" kleptoparasitic spider, Argyrodes lanyuensis Yoshida, Tso & Severinghaus, 1998 in the Philippines. Results showed that, in addition to Orchid/Lanyu Island, this species has a wide geographic distribution in the Philippine Archipelago. The estimated divergence time of this lineage using the mitochondrial cytochrome oxidase 1 (mt-CO1) suggests that this species diverged ca 3.12 MYA, during the Pliocene. Two reciprocal monophyletic clades were elucidated in A. lanyuensis, but with limited differentiation across Pleistocene Aggregate Island Complex (PAIC) boundaries and modern-day islands. However, in our analyses of morphological variation, we identified two phenotypically differentiated units in males (Orchid Island, Taiwan + Luzon, Philippine PAIC populations vs. Palawan + West Visayan + Mindanao PAIC populations). We infer that this species diverged in the southern portion of the Philippine Archipelago and only recently colonized Orchid Island. Our study provides new information on the extensive distribution of A. lanyuensis outside Orchid Island, Taiwan, but we documented a very limited geographically associated genetic variation. Our study points to behavioral phenomena such as foraging behavior as essential contributor to the evolutionary process of species diversification, in contrast to the traditionally invoked geographic drivers of divergence.

Gene Flow Increases Phylogenetic Structure and Inflates Cryptic Species Estimations: A Case Study on Widespread Philippine Puddle Frogs (Occidozyga laevis).

In cryptic amphibian complexes, there is a growing trend to equate high levels of genetic structure with hidden cryptic species diversity. Typically, phylogenetic structure and distance-based approaches are used to demonstrate the distinctness of clades and justify the recognition of new cryptic species. However, this approach does not account for gene flow, spatial, and environmental processes that can obfuscate phylogenetic inference and bias species delimitation. As a case study, we sequenced genome-wide exons and introns to evince the processes that underlie the diversification of Philippine Puddle Frogs-a group that is widespread, phenotypically conserved, and exhibits high levels of geographically based genetic structure. We showed that widely adopted tree- and distance-based approaches inferred up to 20 species, compared to genomic analyses that inferred an optimal number of five distinct genetic groups. Using a suite of clustering, admixture, and phylogenetic network analyses, we demonstrate extensive admixture among the five groups and elucidate two specific ways in which gene flow can cause overestimations of species diversity: 1) admixed populations can be inferred as distinct lineages characterized by long branches in phylograms; and 2) admixed lineages can appear to be genetically divergent, even from their parental populations when simple measures of genetic distance are used. We demonstrate that the relationship between mitochondrial and genome-wide nuclear $p$-distances is decoupled in admixed clades, leading to erroneous estimates of genetic distances and, consequently, species diversity. Additionally, genetic distance was also biased by spatial and environmental processes. Overall, we showed that high levels of genetic diversity in Philippine Puddle Frogs predominantly comprise metapopulation lineages that arose through complex patterns of admixture, isolation-by-distance, and isolation-by-environment as opposed to species divergence. Our findings suggest that speciation may not be the major process underlying the high levels of hidden diversity observed in many taxonomic groups and that widely adopted tree- and distance-based methods overestimate species diversity in the presence of gene flow. [Cryptic species; gene flow; introgression; isolation-by-distance; isolation-by-environment; phylogenetic network; species delimitation.].

Manoalide Shows Mutual Interaction between Cellular and Mitochondrial Reactive Species with Apoptosis in Oral Cancer Cells.

We previously found that marine sponge-derived manoalide induced antiproliferation and apoptosis of oral cancer cells as well as reactive species generations probed by dichloro-dihydrofluorescein diacetate (DCFH-DA) and MitoSOX Red. However, the sources of cellular and mitochondrial redox stresses and the mutual interacting effects between these redox stresses and apoptosis remain unclear. To address this issue, we examined a panel of reactive species and used the inhibitors of cellular reactive species (N-acetylcysteine (NAC)), mitochondrial reactive species (MitoTEMPO), and apoptosis (Z-VAD-FMK; ZVAD) to explore their interactions in manoalide-treated oral cancer Ca9-22 and CAL 27 cells. Hydroxyl (˙OH), nitrogen dioxide (NO2˙), nitric oxide (˙NO), carbonate radical-anion (CO3 ˙-), peroxynitrite (ONOO-), and superoxide (O2 ˙-) were increased in oral cancer cells following manoalide treatments in terms of fluorescence staining and flow cytometry. Cellular reactive species (˙OH, NO2 ·, ˙NO, CO3 ˙-, and ONOO-) as well as cellular and mitochondrial reactive species (O2 ˙-) were induced in oral cancer cells following manoalide treatment for 6 h. NAC, MitoTEMPO, and ZVAD inhibit manoalide-induced apoptosis in terms of annexin V and pancaspase activity assays. Moreover, NAC inhibits mitochondrial reactive species and MitoTEMPO inhibits cellular reactive species, suggesting that cellular and mitochondrial reactive species can crosstalk to regulate each other. ZVAD shows suppressing effects on the generation of both cellular and mitochondrial reactive species. In conclusion, manoalide induces reciprocally activation between cellular and mitochondrial reactive species and apoptosis in oral cancer cells.

A survey on poorly known rainforest litter-dwelling spiders of Orchid Island (Lanyu, Taiwan) with the description of a new species (Araneae: Linyphiidae, Tetrablemmidae, and Theridiosomatidae).

Representatives of some poorly known spider species collected in the rainforest litter of the Orchid Island (Taiwan) are illustrated and discussed here. A new species, Brignoliella tao sp. nov. (Fam. Tetrablemmidae), endemic to Orchid Island, is described based on both sexes. The previously unknown female of Theridiosoma triumphale Zhao Li, 2012 (Fam. Theridiosomatidae), is described for the first time. Zoma taiwanica (Zhang, Zhu Tso 2006) comb. nov., from the same family, is illustrated and its transfer from the genus Theridiosoma O. Pickard-Cambridge, 1879 to Zoma Saaristo, 1996 is proposed on the basis of morphological characters. Habitus and genitalia of the endemic species Gongylidioides angustus Tu Li, 2006 (Fam. Linyphiidae) are also illustrated.

Gut microbiota compositions and metabolic functions in type 2 diabetes differ with glycemic durability to metformin monotherapy.

AIMS: The metabolic derangements in type 2 diabetes have been attributed to compositional changes in the gut microbiota. Metformin, the first-line treatment for type 2 diabetes, has been found to modulate the gut microbiota. However, no literature has reported the associations between the composition of the gut microbiota and glycemic durability to metformin monotherapy. METHODS: A total of 375 patients with type 2 diabetes were recruited, among which 14 and 11 patients were eligible as the metformin durable group and nondurable group, respectively. Fecal samples were collected to analyze the gut microbiota by Illumina sequencing of the 16S rRNA gene, and PICRUSt2 was adopted to infer microbial functional differences. RESULTS: Although the two groups had similar biochemical profiles and microbial metabolites, the pattern of microbiota clustering was different. The intra-group diversity was significantly reduced in the durable group. For the microbial metabolic pathways, the biosynthesis of thiamine and lipopolysaccharide was dominant in the durable group. CONCLUSIONS: There were different compositions of gut microbiota with unique microbial metabolic pathways between type 2 diabetes with and without glycemic durability to metformin monotherapy. Microbial salvage by increasing thiamine biosynthesis might be beneficial for the metformin durable group to maintain optimal glycemic control.

Phylogenomic Analysis of Ultraconserved Elements Resolves the Evolutionary and Biogeographic History of Segmented Trapdoor Spiders.

The segmented trapdoor spiders (Liphistiidae) are the sole surviving family of the suborder Mesothelae, which forms the sister lineage to all other living spiders. Liphistiids have retained a number of plesiomorphic traits and their present-day distribution is limited to East and Southeast Asia. Studying this group has the potential to shed light on the deep evolutionary history of spiders, but the phylogeny and divergence times of the family have not been resolved with confidence. We performed phylogenomic and molecular dating analyses of 2765 ultraconserved element loci from 185 liphistiid taxa. Our analyses show that the crown group of Liphistiidae appeared in the mid-Cretaceous at 102 Ma (95% credibility interval 92-113 Ma), but it was not until the Neogene that much of the diversification within the family occurred in mainland Southeast and East Asia. This diversification was coincident with tectonic events such as the extension of the East Asian continental margin, as well as geological upheavals in Indochina induced by the collision between India and Asia. Our study highlights the important role of major tectonic events in shaping the evolutionary history, present-day diversity, and geographical distribution of mesothele and liphistiid spiders. [biogeography; concatenation; Liphistiidae; molecular dating; summary coalescent; UCEs.].

Implication of single year seasonal sampling to genetic diversity fluctuation that coordinates with oceanographic dynamics in torpedo scads near Taiwan.

Many fisheries management and conservation plans are based on the genetic structure of organisms in pelagic ecosystems; however, these structures tend to vary over time, particularly in cyclic ocean currents. We performed genetic analyses on the populations of the pelagic fish, Megalaspis cordyla (Osteichthyes: Carangidae) in the area surrounding Taiwan during 2000-2001. Genotyping was performed on M. cordyla collected seasonally around Taiwan as well as specimens collected from Singapore (Malacca strait) and Indonesia (Banda Sea). Gonadosomatic indices (GSI) revealed that M. cordyla does not spawn near Taiwan. Data related to the mitochondrial control region revealed that the samples from Singapore and Indonesia represented two distinct genetic cohorts. Genotyping revealed that during the summer (June-August 2000), the Indonesian variant was dominant in eastern Taiwan (presumably following the Kuroshio Current) and in the Penghu region (following the Kuroshio Branch Current). During the same period, the Singapore genotype was dominant along the western coast of Taiwan (presumably following the South China Sea Current); however, the number dropped during the winter (December-February 2001) under the effects of the China Coast Current. Divergence time estimates indicate that the two genetic cohorts split during the last glacial maximum. Despite the fact that these results are based on sampling from a single year, they demonstrate the importance of seasonal sampling in unravelling the genetic diversity in pelagic ecosystems.

Tracking the evolution of the two successful CC59 methicillin-resistant Staphylococcus aureus clones in Taiwan: the divergence time of the two clades is estimated to be the 1980s.

Clonal complex 59 (CC59) is the dominant community-associated methicillin-resistant Staphylococcus aureus (MRSA) strain in Taiwan and includes the Asian-Pacific clone with Panton-Valentine leukocidin (PVL)-negative/staphylococcal cassette chromosome mec (SCCmec) IVg and the Taiwan clone characterised as PVL-positive/SCCmec V (5C2&5). Nevertheless, data on the evolutionary history of the two dominant CC59 MRSA clones in Taiwan are scarce. In this study, a total of 258 CC59 S. aureus strains from Taiwan were classified by multiple-locus variable-number tandem repeat analysis (MLVA), which revealed two major clusters (MT1 and MT2) with distinct mobile genetic elements (MGEs). However, sequencing and PCR mapping of the ß-lactamase-producing plasmid revealed no difference among all CC59 S. aureus strains. Bayesian evolutionary analysis of 18 of the CC59 S. aureus strains based on core genome alignment revealed two clades: (i) Clade A, which shared the samples with MT1, had the features of mainly harbouring gentamicin-resistant MES6272-2 or MES4578, φSA3 translocation in νSaß and SCCmec IVg; and (ii) Clade B, which shared the samples with MT2, had the features of mainly harbouring streptomycin-resistant MESPM1, PVL phage and SCCmec V (5C2&5). Based on the time-calibrated phylogenetic tree, the estimated time of divergence of the two clades was in the 1980s. These results suggest that the CC59 S. aureus progenitor acquired a ß-lactamase-producing plasmid and then developed the varied genetic backgrounds, which were associated with the acquisition and maintenance of distinct MGEs, leading to differences in antimicrobial susceptibility profiles and molecular virulence determinants.

Parachute geckos free fall into synonymy: Gekko phylogeny, and a new subgeneric classification, inferred from thousands of ultraconserved elements.

Recent phylogenetic studies of gekkonid lizards have revealed unexpected, widespread paraphyly and polyphyly among genera, unclear generic boundaries, and a tendency towards the nesting of taxa exhibiting specialized, apomorphic morphologies within geographically widespread "generalist" clades. This is especially true in Australasia, where monophyly of Gekko proper has been questioned with respect to phenotypically ornate flap-legged geckos of the genus Luperosaurus, the Philippine false geckos of the genus Pseudogekko, and even the elaborately "derived" parachute geckos of the genus Ptychozoon. Here we employ sequence capture targeting 5060 ultraconserved elements (UCEs) to infer phylogenomic relationships among 42 representative ingroup gekkonine lizard taxa. We analyze multiple datasets of varying degrees of completeness (10, 50, 75, 95, and 100 percent complete with 4715, 4051, 3376, 2366, and 772 UCEs, respectively) using concatenated maximum likelihood and multispecies coalescent methods. Our sampling scheme addresses four persistent systematic questions in this group: (1) Are Luperosaurus and Ptychozoon monophyletic, and are any of these named species truly nested within Gekko? (2) Are prior phylogenetic estimates of Sulawesi's L. iskandari as the sister taxon to Melanesian G. vittatus supported by our genome-scale dataset? (3) Is the high-elevation L. gulat of Palawan Island correctly placed within Gekko? (4) And, finally, where do the enigmatic taxa P. rhacophorus and L. browni fall in a higher-level gekkonid phylogeny? We resolve these issues; confirm with strong support some previously inferred findings (placement of Ptychozoon taxa within Gekko; the sister taxon relationship between L. iskandari and G. vittatus); resolve the systematic position of unplaced taxa (L. gulat, and L. browni); and transfer L. iskandari, L. gulat, L. browni, and all members of the genus Ptychozoon to the genus Gekko. Our unexpected and novel systematic inference of the placement of Ptychozoon rhacophorus suggests that this species is not grouped with Ptychozoon or even Luperosaurus (as previously expected) but may, in fact, be most closely related to several Indochinese species of Gekko. With our resolved and strongly supported phylogeny, we present a new classification emphasizing the most inclusive, original generic name (Gekko) for these ~60 taxa, arranged into seven subgenera.

Dual pathways in social evolution: Population genetic structure of group-living and solitary species of kleptoparasitic spiders (Argyrodinae: Theridiidae).

Group-living behavior is taxonomically widespread but rare in spiders. The conventional view is that the main pathways to group-living in spiders are either sub-social, where extended maternal care leads to prolonged sibling association; or communal living, where individuals aggregate to exploit a common resource. Female egg-sac guarding behavior occurs throughout kleptoparasitic spiders in the subfamily Argyrodinae (Theridiidae), while individuals in group-living species cohabit in the resource rich webs of their host spiders. These attributes fit both sub-social and communal routes to group-living, which offers new insights to study the early stages of social evolution. We investigated whether members of kleptoparasitic groups in natural populations comprise related individuals by comparing the population structure of two group-living species, Argyrodes miniaceus and A. cf. fissifrons, and two solitary species, A. fasciatus and Neospintharus trigonum. We found that: (1) genetic-spatial autocorrelation in group-living species was highest among spiders sharing the same host web and declined steeply with increasing distance, but no significant autocorrelation at any scale for solitary species; (2) there was high relatedness among group members in two cases of group-living species, which indicated relatedness was not an adhesive agent in most of the groups, but no high relatedness in solitary species; and (3) the host web boundary was not the sole predictor of genetic structures in group-living species. These results suggest that population genetic structure in the group-living species is caused by limited dispersal of group members that is favored by ecological conditions, including the nature and size of resources. In contrast, the absence of genetic structuring in populations of solitary species indicates a high level of dispersal with individual interactions unlikely to have fitness benefits.

Species delimitation with gene flow: A methodological comparison and population genomics approach to elucidate cryptic species boundaries in Malaysian Torrent Frogs.

Accurately delimiting species boundaries is a nontrivial undertaking that can have significant effects on downstream inferences. We compared the efficacy of commonly used species delimitation methods (SDMs) and a population genomics approach based on genomewide single-nucleotide polymorphisms (SNPs) to assess lineage separation in the Malaysian Torrent Frog Complex currently recognized as a single species (Amolops larutensis). First, we used morphological, mitochondrial DNA and genomewide SNPs to identify putative species boundaries by implementing noncoalescent and coalescent-based SDMs (mPTP, iBPP, BFD*). We then tested the validity of putative boundaries by estimating spatiotemporal gene flow (fastsimcoal2, ABBA-BABA) to assess the extent of genetic isolation among putative species. Our results show that the A. larutensis complex runs the gamut of the speciation continuum from highly divergent, genetically isolated lineages (mean Fst  = 0.9) to differentiating populations involving recent gene flow (mean Fst  = 0.05; Nm  > 5). As expected, SDMs were effective at delimiting divergent lineages in the absence of gene flow but overestimated species in the presence of marked population structure and gene flow. However, using a population genomics approach and the concept of species as separately evolving metapopulation lineages as the only necessary property of a species, we were able to objectively elucidate cryptic species boundaries in the presence of past and present gene flow. This study does not discount the utility of SDMs but highlights the danger of violating model assumptions and the importance of carefully considering methods that appropriately fit the diversification history of a particular system.

Genomic data reveals potential for hybridization, introgression, and incomplete lineage sorting to confound phylogenetic relationships in an adaptive radiation of narrow-mouth frogs.

The microhylid frog genus Kaloula is an adaptive radiation spanning the edge of the Asian mainland and multiple adjacent island archipelagos, with much of the clade's diversity associated with an endemic Philippine radiation. Relationships among clades from the Philippines, however, remain unresolved. With ultraconserved element (UCE) and mitogenomic data, we identified highly supported differences in topology and areas of poor resolution, for each marker set. Using the UCE data, we then identified possible instances of contemporary hybridization, past introgression, and incomplete lineage sorting (ILS) within the Philippine Kaloula. Using a simulation approach, and an estimate of the Philippine Kaloula clade origin (12.7-21.0 mya), we demonstrate that an evolutionary history including inferred instances of hybridization, introgression, and ILS leads to phylogenetic reconstructions that show concordance with results from the observed mitogenome and UCE data. In the process of validating a complex evolutionary scenario in the Philippine Kaloula, we provide the first demonstration of the efficacy of UCE data for phylogenomic studies of anuran amphibians.

Population genetic evidence for sex-specific dispersal in an inbred social spider.

Dispersal in most group-living species ensures gene flow among groups, but in cooperative social spiders, juvenile dispersal is suppressed and colonies are highly inbred. It has been suggested that such inbred sociality is advantageous in the short term, but likely to lead to extinction or reduced speciation rates in the long run. In this situation, very low levels of dispersal and gene flow among colonies may have unusually important impacts on fitness and persistence of social spiders. We investigated sex-specific differences in dispersal and gene flow among colonies, as reflected in the genetic structure within colonies and populations of the African social spider Stegodyphus dumicola Pocock, 1898 (Eresidae). We used DNA fingerprinting and mtDNA sequence data along with spatial mapping of colonies to compare male and female patterns of relatedness within and among colonies at three study sites. Samples were collected during and shortly after the mating season to detect sex-specific dispersal. Distribution of mtDNA haplotypes was consistent with proliferation of social nests by budding and medium- to long-distance dispersal by ballooning females. Analysis of molecular variance and spatial autocorrelation analyses of AFLPs showed high levels of genetic similarity within colonies, and STRUCTURE analyses revealed that the number of source populations contributing to colonies ranged from one to three. We also showed significant evidence of male dispersal among colonies at one site. These results support the hypothesis that in social spiders, genetic cohesion among populations is maintained by long-distance dispersal of female colony founders. Genetic diversity within colonies is maintained by colony initiation by multiple dispersing females, and adult male dispersal over short distances. Male dispersal may be particularly important in maintaining gene flow among colonies in local populations.

Phylogeny of the island archipelago frog genus Sanguirana: Another endemic Philippine radiation that diversified 'Out-of-Palawan'.

Recent higher-level frog phylogenetic analyses have included a few members of the endemic Philippine frog genus Sanguirana. Although the monophyly of the group has never been disputed, the recent phylogenetically-supported inclusion of the Palawan Wood Frog (Sanguirana sanguinea) in this clade was highly unexpected. In addition, species boundaries and relationships remain unclear and new species continue to be discovered. We estimate the phylogeny for this endemic Philippine genus using two mitochondrial gene regions and six nuclear loci and complete sampling for all known species. We use a time-calibrated Bayesian estimate of phylogeny and model-testing approach to biogeographic inference to infer ancestral areas and probable means of diversification. These analyses identify Sanguirana as an additional clade for which the 'Out-of-Palawan' biogeographic scenario is unambiguously preferred. This study lends additional support to recent work suggesting that a substantial portion of Philippine vertebrate megadiversity originated via colonization of the archipelago from the Palawan microcontinent, with subsequent invasion of oceanic islands (e.g., range expansion over Huxley's Modification of Wallace's Line), numerous instances of overwater dispersal, and geographic radiation across the archipelago.

Archipelago colonization by ecologically dissimilar amphibians: evaluating the expectation of common evolutionary history of geographical diffusion in co-distributed rainforest tree frogs in islands of Southeast Asia.

Widespread, co-distributed species with limited relative dispersal abilities represent compelling focal taxa for comparative phylogeography. Forest vertebrates in island archipelagos often exhibit pronounced population structure resulting from limited dispersal abilities or capacity to overcome marine barriers to dispersal. The exceptionally diverse Old World tree frogs of the family Rhacophoridae have colonized the forested island archipelagos of Southeast Asia on multiple occasions, entering the islands of Indonesia and the Philippines via a "stepping stone" mode of dispersal along elongate island chains, separated by a series of marine channels. Here we evaluate the prediction that two tightly co-distributed Philippine rhacophorids colonized the archipelago during concomitant timescales and in the same, linear, "island-hopping" progression. We use a new multilocus dataset, utilize dense genetic sampling from the eastern arc of the Philippines, and we take a model-based phylogeographic approach to examining the two species for similar topological patterns of diversification, genetic structure, and timescales of diversification. Our results support some common mechanistic predictions (a general south-to-north polarity of colonization) but not others (timescale for colonization and manner and degree of lineage diversification), suggesting differing biogeographic scenarios of geographical diffusion through the archipelago and unique and idiosyncratic ecological capacities and evolutionary histories of each species.

Biogeography and speciation patterns of the golden orb spider genus Nephila (Araneae: Nephilidae) in Asia.

The molecular phylogeny of the globally distributed golden orb spider genus Nephila (Nephilidae) was reconstructed to infer its speciation history, with a focus on SE Asian/W Pacific species. Five Asian, two Australian, four African, and one American species were included in the phylogenetic analyses. Other species in Nephilidae, Araneidae, and Tetragnathidae were included to assess their relationships with the genus Nephila, and one species from Uloboridae was used as the outgroup. Phylogenetic trees were reconstructed from one nuclear (18S) and two mitochondrial (COI and 16S) markers. Our molecular phylogeny shows that the widely distributed Asian/Australian species, N. pilipes, and an African species, N. constricta, form a clade that is sister to all other Nephila species. Nested in this Nephila clade are one clade with tropical and subtropical/temperate Asian/Australian species, and the other containing African and American species. The estimated divergence times suggest that diversification events within Nephila occurred during mid-Miocene to Pliocene (16 Mya-2 Mya), and these time periods were characterized by cyclic global warming/cooling events. According to Dispersal and Vicariance Analysis (DIVA), the ancestral range of the Asian/Australian clade was tropical Asia, and the ancestral range of the genus Nephila was either tropical Asia or Africa. We conclude that the speciation of the Asian/Australian Nephila species was driven by Neogene global cyclic climate changes. However, further population level studies comparing diversification patterns of sister species are needed to determine the mode of speciation of these species.