Conservation biology of Malagasy strepsirhines: a phylogenetic approach

The phylogenetic diversity of extant lemurs represents one of the most important but least studied aspects of the conservation biology of primates. The phylogenetic diversity of a species is inversely proportional to the relative number and closeness of its phylogenetic relatives. Phylogenetic diversity can then be used to determine conservation priorities for specific biogeographic regions. Although Malagasy strepsirhines represent the highest phylogenetic diversity among primates at the global level, there are few phylogenetic data on species-specific and regional conservation plans for lemurs in Madagascar. Therefore, in this paper the following questions are addressed for extant lemurs: 1) how does the measure of taxonomic uniqueness used by Mittermeier et al. (1992 Lemurs of Madagascar; Gland, Switzerland: IUCN) equate with an index of phylogenetic diversity, 2) what are the regional conservation priorities based on analyses of phylogenetic diversity in extant lemurs, and 3) what conservation recommendations can be made based on analyses of phylogenetic diversity in lemurs? Taxonomic endemicity standardized weight (TESW) indices of phylogenetic diversity were used to determine the evolutionary component of biodiversity and to prioritize regions for conserving lemur taxa. TESW refers to the standardization of phylogenetic diversity indices for widespread taxa and endemicity of species. The phylogenetic data came from recent genetic studies of Malagasy strepsirhines at the species level. Lemur species were assigned as being either present or absent in six biogeographic regions. TESW indices were combined with data on lemur complementarity and protected areas to assign conservation priorities at the regional level. Although there were no overall differences between taxonomic ranks and phylogenetic rankings, there were significant differences for the top-ranked taxa. The phylogenetic component of lemur diversity is greatest for Daubentonia madagascariensis, Allocebus trichotis, Lepilemur septentrionalis, Indri indri, and Mirza coquereli. Regional conservation priorities are highest for lemurs that range into northeast humid forests and western dry forests. Expansion of existing protected areas in these regions may provide the most rapid method for preserving lemurs. In the long term, new protected areas must be created because there are lemur species that: 1) are not found in existing protected areas, 2) exist only in one or two protected areas, and 3) are still being discovered outside the current network of protected areas. Data on the population dynamics and feeding ecology of phylogenetically important species are needed to ensure that protected areas adequately conserve lemur populations in Madagascar.     

Large rivers do not always act as species barriers for Lepilemur sp.

Sportive lemurs constitute a highly diverse endemic lemur family (24 species) for which many biogeographic boundaries are not yet clarified. Based on recent phylogeographic models, this study aims to determine the importance of two large rivers (the Antainambalana and Rantanabe) in northeastern Madagascar as species barriers for Lepilemur seali. The Antainambalana River was previously assumed to act as the southern border of its distribution. A total of 1,038 bp of the mtDNA of four individuals stemming from two adjacent inter-river systems south of the Antainambalana River was sequenced and compared to sequences of 22 described Lepilemur species. The phylogenetic reconstruction did not find support for either of the two rivers as species barrier for Lepilemur, as all captured individuals clustered closely with and therefore belonged to L. seali. However, a previously published sequence of an individual from a site south of our study sites belongs to a separate species. The southern boundary of L. seali must therefore be one of two large rivers further south of our study sites. The results suggest that L. seali may possess a relatively large altitudinal range that enabled this species to migrate around the headwaters of the Antainambalana and Rantanabe Rivers. Previous phylogeographic models need to be refined in order to incorporate these findings, and more species-specific altitudinal range data are urgently needed in order to fully understand the biogeographic patterns of lemurs on Madagascar.     

Density estimates of two endangered nocturnal lemur species from northern Madagascar: new results and a comparison of commonly used methods

Very little information is known of the recently described Microcebus tavaratra and Lepilemur milanoii in the Daraina region, a restricted area in far northern Madagascar. Since their forest habitat is highly fragmented and expected to undergo significant changes in the future, rapid surveys are essential to determine conservation priorities. Using both distance sampling and capture-recapture methods, we estimated population densities in two forest fragments. Our results are the first known density and population size estimates for both nocturnal species. In parallel, we compare density results from four different approaches, which are widely used to estimate lemur densities and population sizes throughout Madagascar. Four approaches (King, Kelker, Muller and Buckland) are based on transect surveys and distance sampling, and they differ from each other by the way the effective strip width is estimated. The fifth method relies on a capture-mark-recapture (CMR) approach. Overall, we found that the King method produced density estimates that were significantly higher than other methods, suggesting that it generates overestimates and hence overly optimistic estimates of population sizes in endangered species. The other three distance sampling methods provided similar estimates. These estimates were similar to those obtained with the CMR approach when enough recapture data were available. Given that Microcebus species are often trapped for genetic or behavioral studies, our results suggest that existing data can be used to provide estimates of population density for that species across Madagascar.     

SmTRC1, a novel Schistosoma mansoni DNA transposon, discloses new families of animal and fungi transposons belonging to the CACTA superfamily

Background

The number of species within the Malagasy genus Lepilemur and their phylogenetic relationships is disputed and controversial. In order to establish their evolutionary relationships, a comparative cytogenetic and molecular study was performed. We sequenced the complete mitochondrial cytochrome b gene (1140 bp) from 68 individuals representing all eight sportive lemur species and most major populations, and compared the results with those obtained from cytogenetic studies derived from 99 specimens.

Results

Interspecific genetic variation, diagnostic characters and significantly supported phylogenetic relationships were obtained from the mitochondrial sequence data and are in agreement with cytogenetic information. The results confirm the distinctiveness of Lepilemur ankaranensis, L. dorsalis, L. edwardsi, L. leucopus, L. microdon, L. mustelinus, L. ruficaudatus and L. septentrionalis on species level. Additionally, within L. ruficaudatus large genetic differences were observed among different geographic populations. L. dorsalis from Sahamalaza Peninsula and from the Ambanja/Nosy Be region are paraphyletic, with the latter forming a sister group to L. ankaranensis.

Conclusion

Our results support the classification of the eight major sportive lemur taxa as independent species. Moreover, our data indicate further cryptic speciation events within L. ruficaudatus and L. dorsalis. Based on molecular data we propose to recognize the sportive lemur populations from north of the Tsiribihina River, south of the Betsiboka River, and from the Sahamalaza Peninsula, as distinct species.     

Taxonomic relationships and sampling effects among Lepilemuridae and Lemuridae using a partial cytochrome b gene

Partial cytochrome b sequences were used to study relationships between three Lepilemuridae species (Lepilemur dorsalis, L. septentrionalis and L. leucopus) and other Lemuridae species. L. dorsalis were subdivided into two sub-groups, according to their capture area (Nosy-Be island and Sahamalaza peninsula). Relationships deduced from phylogenetic trees as well as genetic distances lead to the classification of the Lepilemurs analysed here into separate species. These Lepilemurs form a monophyletic clade which is the sister clade of all other Lemurs used in this study. Reconstructions using randomly chosen sequences and step by step addition of sequences indicate that phylogenetic results for closely related species need to be analysed with caution, if only a small number of sequences are used to obtain them.     

Linking phylogenetics with population genetics to reconstruct the geographic origin of a species

Reconstructing ancestral geographic origins is critical for understanding the long-term evolution of a species. Bayesian methods have been proposed to test biogeographic hypotheses while accommodating uncertainty in phylogenetic reconstruction. However, the problem that certain taxa may have a disproportionate influence on conclusions has not been addressed. Here, we infer the geographic origin of Drosophila simulans using 2,014 bp of the period locus from 63 lines collected from 18 countries. We also analyze two previously published datasets, alcohol dehydrogenase related and NADH:ubiquinone reductase 75 kDa subunit precursor. Phylogenetic inferences of all three loci support Madagascar as the geographic origin of D. simulans. Our phylogenetic conclusions are robust to taxon resampling and to the potentially confounding effects of recombination. To test our phylogenetically derived hypothesis we develop a randomization test of the population genetics prediction that sequences from the geographic origin should contain more genetic polymorphism than those from derived populations. We find that the Madagascar population has elevated genetic polymorphism relative to non-Madagascar sequences. These data are corroborated by mitochondrial DNA sequence data.     

Phylogeography of Ptychadena mascareniensis suggests transoceanic dispersal in a widespread African-Malagasy frog lineage

Aim The Mascarene ridged frog, Ptychadena mascareniensis, is the only African amphibian species thought to occur on Madagascar and on the Seychelles and also Mascarene islands. We explored its phylogenetic relationships and intraspecific genetic differentiation to contribute to the understanding of transoceanic dispersal in amphibians. Methods Fragments of the mitochondrial 16S rRNA gene were sequenced from specimens collected over most of the distribution area of P. mascareniensis, including populations from Madagascar, Mascarenes and Seychelles. Results We identified five deeply divergent clades having pairwise divergences >5%, which probably all represent cryptic species in a P. mascareniensis complex. One of these seems to be restricted to Madagascar, the Mascarenes and the Seychelles. Sequences obtained from topotypic material (Réunion) were identical to the most widespread haplotype from Madagascar. The single Mauritian/Seychellean haplotype differed by only one mutation from a Malagasy haplotype. Main conclusions It is likely that the Mascarene and Seychellean populations were introduced from Madagascar by humans. In contrast, the absence of the Malagasy haplotypes from Africa and the distinct divergences among Malagasy populations (16 mutations in one divergent hapolotype from northern Madagascar) suggest that Madagascar was populated by Ptychadena before the arrival of humans c. 2000 years ago. Because Madagascar has been separated from Africa since the Jurassic, this colonization must have taken place by overseas rafting, which may be a more widespread dispersal mode in amphibians than commonly thought.     

Genomic data reveal deep genetic structure but no support for current taxonomic designation in a grasshopper species complex

Taxonomy has traditionally relied on morphological and ecological traits to interpret and classify biological diversity. Over the last decade, technological advances and conceptual developments in the field of molecular ecology and systematics have eased the generation of genomic data and changed the paradigm of biodiversity analysis. Here we illustrate how traditional taxonomy has led to species designations that are supported neither by high throughput sequencing data nor by the quantitative integration of genomic information with other sources of evidence. Specifically, we focus on Omocestus antigai and Omocestus navasi, two montane grasshoppers from the Pyrenean region that were originally described based on quantitative phenotypic differences and distinct habitat associations (alpine vs. Mediterranean‐montane habitats). To validate current taxonomic designations, test species boundaries, and understand the factors that have contributed to genetic divergence, we obtained phenotypic (geometric morphometrics) and genome‐wide SNP data (ddRADSeq) from populations covering the entire known distribution of the two taxa. Coalescent‐based phylogenetic reconstructions, integrative Bayesian model‐based species delimitation, and landscape genetic analyses revealed that populations assigned to the two taxa show a spatial distribution of genetic variation that do not match with current taxonomic designations and is incompatible with ecological/environmental speciation. Our results support little phenotypic variation among populations and a marked genetic structure that is mostly explained by geographic distances and limited population connectivity across the abrupt landscapes characterizing the study region. Overall, this study highlights the importance of integrative approaches to identify taxonomic units and elucidate the evolutionary history of species.     

Solving alpha‐diversity by morphological markers contributes to arranging the systematic status of a crayfish species complex (Crustacea,Decapoda)

Since innovative molecular approaches in phylogenetics solely based on small gene fragments have often generated widely complicated interpretations of crayfish diversity, we propose a geometric morphometric study integrated with previous molecular data to provide robust estimates of phylogeny and classification of the Austropotamobius pallipes complex, genetically divided into several species and subspecies. We discuss whether cephalothorax shape variation can show phylogenetic signals congruent to those derived from analyses of mitochondrial and nuclear markers. Our results support the hypothesis that carapace form is potentially informative in the reconstruction of crayfish phylogeny. In the phenetic analyses, populations collected within the Italian territory form different unexpected clusters, each involving distant populations of different genetic haplogroups, suggesting a within‐species convergence probably due to a series of local adaptations. The phylogenetic analysis performed using a neighbour‐joining algorithm showed interesting relationships amongst the studied populations. In particular, the geometric morphometric matrices showed a slight congruence with some genetic distances, allowing the discrimination of three major lineages: (1) Istran + Apennine group; (2) Arno group; (3) north‐western group. Finally, our observations support some molecular data with a lighter phylogenetic signal that do not suggest a strong separation of A. pallipes into clades and sub‐clades.     

Do diversification models of Madagascar’s biota explain the population structure of the endemic bat Myotis goudoti (Chiroptera: Vespertilionidae)?

Aim Three mechanisms have been proposed to explain the adaptive radiations and species diversifications of Madagascar’s biota: the ecogeographical constraint, the riverine barrier and the micro‐endemism models. On the intraspecific level, each model predicts different patterns of gene flow across the island’s physical and ecological features. To evaluate these models, phylogeographical analyses were conducted on a widespread and endemic species of bat, Myotis goudoti (Vespertilionidae). Location Madagascar. Methods In order to reconstruct the phylogeographical history of M. goudoti, the mitochondrial D‐loop and the cytochrome b gene were sequenced for 195 bats from 41 localities. Phylogenetic reconstructions and a minimum spanning tree were used to infer haplotype relationships. The effect of barriers on gene flow was evaluated using analyses of molecular variance and pairwise population differentiation. Mismatch distribution and coalescence‐based estimates were conducted to infer the demographic history of M. goudoti. Results The sequenced individuals showed 159 distinct D‐loop haplotypes, most of them being unique to a single location. Populations were significantly structured (Φ_ST = 0.170, P < 0.001) across Madagascar, but only a minor part of the overall genetic variance was explained by any of the three models. Shared ancestry of lineages across most physical or ecological barriers was common, whereas the uncovered genetic differences between southern and central‐northern populations were unexpected. Main conclusions Major barriers predicted by the three biogeographical models do not explain the segregation of mitochondrial lineages of M. goudoti across Madagascar. This is not simply attributable to the high dispersal ability of this species, as populations are notably structured. The genetic contrast between southern and central‐northern populations, separated by a zone of admixture, suggests that these areas currently support populations that expanded during the Late Pleistocene. This latitudinal differentiation of populations has been observed in less vagile animals, such as geckos and lemurs, suggesting that climate fluctuations of the Pleistocene had an impact across several groups and resulted in northern and southern refugia in Madagascar.     

Integrative taxonomy and phylogeny of leafless Vanilla orchids from the South-West Indian Ocean region reveal two new Malagasy species

The leafless Vanilla species complex from the South-West Indian Ocean (SWIO) region has long been a taxonomic challenge, due to limited patterns of morphological differentiation and an absence of variation within chloroplast sequences. This complex includes seven known morphospecies: V. madagascariensis, V. bosseri, V. decaryana, and V. perrieri endemic to Madagascar, V. humblotii presumed as endemic to the Comoros Archipelago, but also present in Madagascar, V. roscheri from the East African coast, and V. phalaenopsis endemic to Seychelles. A previous population genetic study using microsatellite markers allowed us to distinguish, in addition to the five recognized Malagasy taxa, two other genetic clusters present in the East of the island. An integrative taxonomy approach was therefore conducted by combining microsatellite and morphological data used in the previous study with new data sets, and by adding ITS sequencing data, to validate the taxonomic level of these Malagasy genetic clusters and unravel phylogenetic relationships between SWIO species. As a result, based on phylogenetic, genotypic and morphological evidence, nine species were discriminated in the SWIO region, including seven in Madagascar, with two new eastern species. The leafless Vanilla group originated and diversified in Madagascar, from an ancestor of African descent, with three subsequent independent colonization events from Madagascar to the other territories of SWIO within the two main lineages (white versus yellow flower species). The new Malagasy species, V. allorgeae Andriamihaja & Pailler sp. nov., and V. atsinananensis Andriamihaja & Pailler sp. nov., are described and a new identification key is proposed.     

The influence of mating system,demography, parasites and colonization on the population structure of Biomphalaria pfeifferi in Madagascar

Current evolutionary forces and historical processes interact to shape the distribution of neutral genetic variability within and among populations. Focusing on the genetics of recently introduced organisms offers a good opportunity to understand the relative importance of these factors. This study concerns variation at 8 polymorphic microsatellite loci in 30 populations of Biomphalaria pfeifferi. The sampling area spans most of the species' range in Madagascar where it was probably introduced recently. Extremely low variation was found within all populations studied, which may partly result from high selfing rates. However, this cannot account for the variance of variation across populations, which is better explained by habitat openness (that reflects environmental stochasticity), the prevalence of the parasitic trematode Schistosoma mansoni and historical demography (colonization and subsequent bottlenecks). Large global differentiation was also observed, suggesting that current gene flow among populations is limited to small distances, within watersheds and to few individuals. Our data set also allowed us to test several hypotheses regarding colonization, based on bottleneck and admixture tests. The observed pattern requires at least two independent introductions from slightly differentiated genetic sources in the western part of Madagascar. Another introduction, from a very different genetic origin, should also be postulated to explain the genetic composition of eastern populations. That this introduction occurred recently suggests that the colonization of Madagascar by B. pfeifferi is an ongoing process.     

Mitochondrial evidence for distinct phylogeographic units in the endangered Malagasy poison frog Mantella bernhardi

Mantella bernhardi is an endemic species of Malagasy poison frog threatened by loss and fragmentation of its natural habitat and collection for the pet trade. It is classified as threatened according to the International Union for Conservation of Nature and Natural Resources (IUCN) categories and included in Appendix II of the Convention on the International Trade of Endangered Species (CITES). A recent survey has increased the known distributional range of the species from one to eight populations across southeastern Madagascar, but little is known about its biology and genetic diversity. Here we estimate inter- and intrapopulation mitochondrial genetic variation of four populations. Populations from the northern and southern parts of the distributional range showed a high degree of divergence (maximum of 11.35% in cytochrome b) and were recovered as reciprocally monophyletic groups. Nine haplotypes were detected in the northern and 12 in the southern populations. The population from Ranomafana National Park showed the lowest number of haplotypes and nucleotide diversity, and shared its most common haplotype with the second northern population from Tolongoina. All the other detected haplotypes were unique to each of the four populations. This suggests the existence of important barriers to gene flow, pre-dating human colonization of Madagascar at about 2000 years ago, in distinct contrast to other Mantella species that show a high degree of haplotype sharing throughout their range. The continued habitat fragmentation within the distribution range of M. bernhardi prevents any connection between its populations. Our data indicate the existence of at least two different management units for conservation in this species, corresponding to the North and South of its distribution range, and highlight the existence of strong regional endemism in southeastern Madagascar.     

赣中南花猪随机扩增多态DNA与群体遗传关系的研究

用RAPD技术检测了泰和冠朝猪、永丰藤田花猪、瑞金三花猪、兴国茶园猪、上犹花猪、万安花猪、乐安花猪等7个赣中南花猪地方类群基因组混合DNA的多态性,经80个随机引物扩增筛选,16个引物产生了共44个多态标记。遗传距离指数计算结果显示：泰和冠朝猪和瑞金三花猪亲缘关系最近,而兴国茶园猪与乐安花猪遗传距离最远。各类群的UPMGA和NJ聚类分析结果与采用生化、免疫和细胞遗传标记分析的结论不尽相同,在此基础上,结合现行分类方法,认为各受试猪群可暂时归并为赣中南花猪类型,但对泰和冠朝猪和万安花猪的品种归属性应作进一步分析。 Abstract: Random amplified polymorphic DNAs (RAPDs) were used to investigate bulked genomic DNA polymorphism of seven pig populations including Taihe Guanchao,Yongfeng Tengtian Spotted,Ruijin Spotted,Xingguo Chayuan,Shangyou Spotted,Wanan Spotted,and Lean Spotted pig.Eighty random primers were screened,of them,16 primers generated polymorphic markers with total number of 44.The genetic distance index matrix indicated that the genetic relationship between Taihe Gaunchao and Ruijin Spotted pig population was the closest,while that between Xingguo Chayuan and Laan Spotted pig population was the farthest.Our molecular phylogenetic trees constructed by UPMGA and NJ methods were in general consistent with that based on biochemical,immunogenetic and cellular genetic markers except for differences in some populations.It was inferred from this study that all pig populations examined could be temporary classified into one breed,however,the population genetic character of Taihe Guanchao and Wanan Spotted pig populations should be further evaluated.     

Geographic variation in loud calls of sportive lemurs (Lepilemur ssp.) and their implications for conservation

Bioacoustical studies in nonhuman primates have shown that loud calls can be reliably used as a noninvasive diagnostic tool for discriminating cryptic taxa, for their monitoring in the field as well as for the reconstruction of their phylogeny. To date, it is unknown, whether loud calls can be used for these purposes in sportive lemurs, for which current genetic studies suggest the existence of at least 24 cryptic species. The aim of this study was to compare the structure of loud calls of populations of sportive lemurs to characterize informative acoustic traits for taxa discrimination and to establish a phylogenetic tree based on acoustic structure. We have based our study on Inter-River-Systems (IRSs) as operational taxonomic units. Samples were collected from nine different localities of four IRSs along a transect from northwestern to northern Madagascar. Two call types, the ouah and the high-pitched call, were present in almost all IRSs. Six temporal and eight spectral parameters were measured in 196 calls of the best quality given by 21 different males. Variation within and between IRSs was assessed by multivariate statistics. Loud calls differed significantly among the different IRSs. The IRSs varied most in spectral parameters, whereas temporal parameters were less variable. Phylogenetic analysis using parsimony yielded 11 out of 17 acoustic characters as phylogenetically informative. The acoustic tree had an average branch support of 78%. Its topology coincided less with geographic distances than with genetic tree topology. Altogether our findings revealed that loud calls separated geographically isolated populations of sportive lemurs specifically. Based on these results, noninvasive tools for diagnosis and monitoring of cryptic species in nature can be developed for conservation management.     

Genetic Differentiation among Natural Populations of Lepilemur ruficaudatus

We studied the genetic differentiation of five populations of red-tailed sportive lemur Lepilemur ruficaudatus by means of allozyme variability and RAPD polymorphisms in order to test whether the Tsiribihina River separates the distribution areas of Lepilemur ruficaudatus and and L. edwardsi. Genetic data as well as the karyotype of a male individual clearly indicate that the Andramasay Forest in the north of Tsiribihina River is inhabited by Lepilemur ruficaudatus and not by L. edwardsi. We propose that the distribution of the two species are separated by the Manambolo River. However, the northernmost population of Lepilemur ruficaudatus inhabiting the Andramasay Forest is gentically differentiated from those that inhabit the dry forest in the south of Tsiribihina River.     

Endemism and diversification in freshwater insects of Madagascar revealed by coalescent and phylogenetic analysis of museum and field collections

The biodiversity and endemism of Madagascar are among the most extraordinary and endangered in the world. This includes the island’s freshwater biodiversity, although detailed knowledge of the diversity, endemism, and biogeographic origin of freshwater invertebrates is lacking. The aquatic immature stages of mayflies (Ephemeroptera) are widely used as bio-indicators and form an important component of Malagasy freshwater biodiversity. Many species are thought to be microendemics, restricted to single river basins in forested areas, making them particularly sensitive to habitat reduction and degradation. The Heptageniidae are a globally diverse family of mayflies (>500 species) but remain practically unknown in Madagascar except for two species described in 1996. The standard approach to understanding their diversity, endemism, and origin would require extensive field sampling on several continents and years of taxonomic work followed by phylogenetic analysis. Here we circumvent this using museum collections and freshly collected individuals in a combined approach of DNA taxonomy and phylogeny. The coalescent-based GMYC analysis of DNA barcode data (mitochondrial COI) revealed 14 putative species on Madagascar, 70% of which were microendemics. A phylogenetic analysis that included African and Asian species and data from two mitochondrial and four nuclear loci indicated the Malagasy Heptageniidae are monophyletic and sister to African species. The genus Compsoneuria is shown to be paraphyletic and the genus Notonurus is reinstalled for African and Malagasy species previously placed in Compsoneuria. A molecular clock excluded a Gondwanan vicariance origin and instead favoured a more recent overseas colonization of Madagascar. The observed monophyly and high microendemism highlight their conservation importance and suggest the DNA-based approach can rapidly provide information on the diversity, endemism, and origin of freshwater biodiversity. Our results underline the important role that museum collections can play in molecular studies, especially in critically endangered biodiversity hotspots like Madagascar where entire species or populations may go extinct very quickly.     

Phylogeographic structure of the fire ant Solenopsis invicta in its native South American range: roles of natural barriers and habitat connectivity

We generated mitochondrial DNA (mtDNA) sequence data from 402 individuals of the fire ant Solenopsis invicta collected from 11 native populations and analyzed these data using a combination of demographic, phylogenetic, and phylogeographic methods to infer features of the evolutionary history of this species. Prior expectations regarding high levels of genetic structure and isolation by distance among populations were supported by the data, but we also discovered several unanticipated patterns. Our analyses revealed a major genetic break between S. invicta mtDNA haplotypes that coincides with the Mesopotamia wetlands region of South America, resulting in two higher level nested clade groupings. In addition, we identified contrasting patterns of genetic differentiation within these two major groups, which may reflect differences in connectivity of suitable habitat in different parts of the native range of S. invicta. Our study represents the first attempt to understand the phylogeographic history of S. invicta across its native range.