Biogeographic barriers,Pleistocene refugia,and climatic gradients in the southeastern Nearctic drive diversification in cornsnakes (Pantherophis guttatus complex)

The southeastern Nearctic is a biodiversity hotspot that is also rich in cryptic species. Numerous hypotheses (e.g., vicariance, local adaptation, and Pleistocene speciation in glacial refugia) have been tested in an attempt to explain diversification and the observed pattern of extant biodiversity. However, previous phylogeographic studies have both supported and refuted these hypotheses. Therefore, while data support one or more of these diversification hypotheses, it is likely that taxa are forming within this region in species‐specific ways. Here, we generate a genomic data set for the cornsnakes (Pantherophis guttatus complex), which are widespread across this region, spanning both biogeographic barriers and climatic gradients. We use phylogeographic model selection combined with hindcast ecological niche models to determine regions of habitat stability through time. This combined approach suggests that numerous drivers of population differentiation explain the current diversity of this group of snakes. The Mississippi River caused initial speciation in this species complex, with more recent divergence events linked to adaptations to ecological heterogeneity and allopatric Pleistocene refugia. Lastly, we discuss the taxonomy of this group and suggest there may be additional cryptic species in need of formal recognition.     

Effects of vicariant barriers, habitat stability, population isolation and environmental features on species divergence in the south-western Australian coastal reptile community

Identifying explicit hypotheses regarding the factors determining genetic structuring within species can be difficult, especially in species distributed in historically dynamic regions. To contend with these challenges, we use a framework that combines species distribution models, environmental data and multi-locus genetic data to generate and explore phylogeographic hypotheses for reptile species occupying the coastal sand-dune and sand-plain habitats of the south-western Australian biodiversity hotspot, a community which has both a high diversity of endemics and has varied dramatically in spatial extent over time. We use hierarchical amova, summary statistic and distance-based analyses to explicitly test specific phylogeographic hypotheses. Namely, we test if biogeographic vicariance across barriers, habitat stability, population isolation along a linear habitat or fragmentation across different environments can explain genetic divergence within five co-distributed squamate reptile species. Our results show that patterns of genetic variation reflect complex and species-specific interactions related to the spatial distribution of habitats present currently and during repeated glacial minima, as opposed to being associated with historical factors such as habitat stability between glacial and inter-glacial periods or vicariant barriers. We suggest that the large impact of habitat characteristics over time (i.e. relative levels of habitat connectivity, climatic gradients and spatial heterogeneity of soil types) reflects the ecological restrictions of the sand-dune and sand-plain reptile communities and may explain the lack of concordance across taxa. The study demonstrates the general utility of the approach for assemblage-level, as well as single species, phylogeographic study, including its usefulness for exploring biologically informed hypotheses about what factors have influenced patterns of genetic variation.     

Dispersal to or from an African biodiversity hotspot?

Biodiversity hotspots are centres of endemism and thus contain many range-restricted species. In addition, within these hotspots occur widespread species that might have originated within a hotspot before dispersing to neighbouring or distant regions. We test this hypothesis with a phylogeographic analysis of a miniature leaf litter frog, Arthroleptis xenodactyloides , that has a large distribution throughout the Eastern Arc biodiversity hotspot and other regions in East Africa. Maximum-likelihood and Bayesian estimates of the mitochondrial gene phylogeny are used as a proxy for understanding the evolutionary history of diversification and the historical relationships between populations. The north–south range of this species extends for approximately 1900 km; our sampling covers approximately 85% of this range. Using phylogenetic comparative methods, we estimate the region of origin and direction of dispersal within A. xenodactyloides . We compare contrasting hypotheses of latitudinal range expansion using bayes factors. The ancestral region of origin of A. xenodactyloides is reconstructed as having occurred within the Eastern Arc before dispersing southwards into the southern Rift Mountains, probably in the Pleistocene. The phylogeographic structure within this leaf litter frog is surprisingly similar to that of forest birds, revealing that similar geographic features might have had a driving role in diversification of these very dissimilar taxa. Latitudinal expansion occurred early in the evolutionary history of A. xenodactyloides , which may indicate that physiological adaptation facilitated its wide geographic distribution.     

Comparative phylogeography and demographic history of two marsupials of the Atlantic Forest in eastern Brazil

The Atlantic Forest biodiversity hotspot in eastern South America has been the focus of several phylogeographic studies concerning relationships between populations and areas and how taxa respond to environmental changes. We infer and compare the demographic and biogeographic histories of two didelphid marsupial species, Gracilinanus microtarsus and Marmosops incanus, from the Atlantic Forest of eastern Brazil to determine how these species responded to environmental changes over time, using mitochondrial and nuclear DNA sequences. We found great intraspecific genetic divergence in both species and a strong geographic structure related to similar and spatially cohesive groups within each species. These groups are consistent with the same topographical barriers, such as mountains and river valleys. Intraspecific clades are very old, dating back to a period of tectonic activities in the Neogene (5.39–8.57 Mya). Changes in the environment over the last 7 million years lead to fairly concordant demographic changes in both marsupial species, including population expansion during the last glacial maximum (ca. 21,000 years ago) or last interglacial (ca. 120,000 years ago) or both. These results do not fit the Pleistocene refuge hypothesis as an explanation of the historical biogeography and diversification of both species in the Atlantic Forest, but are compatible with the Atlantis Forest hypothesis.     

Comparative phylogeography and the history of endemic vertebrates in the Wet Tropics rainforests of Australia

We examine the effects of historical climate change on vertebrate differentiation in tropical rainforest by comparing phylogeographic patterns in six species of widespread rainforest-restricted herpetofauna from throughout the Wet Tropics of Australia. Qualitative and quantitative comparisons of phylogeographic structure reveal strikingly similar patterns of pre-Pleistocene vicariant population differentiation on either side of a previously identified biogeographic break (variously referred to as the Black Mountain Barrier or Corridor; BMC). While divergence across the BMC antedates the Pleistocene, the impact of Quaternary climate change is apparent in populations on either side of the BMC. Consistent with palaeoclimatological reconstructions for the region, the distribution and degree of mtDNA diversity suggests that populations were fragmented and reduced to multiple refugia during Pleistocene glacial periods, with expansion following Holocene rainforest recovery. This pattern is repeated on both sides of the BMC, but substantial differences in the amount and distribution of mtDNA diversity within species indicate the importance of species-specific ecological characteristics. The historical processes of extinction and (re)colonization revealed by the comparative phylogeographic analysis of mtDNA sequences substantiate earlier suggestions that current regional patterns of species distribution and diversity in the Wet Tropics are largely determined by local extinctions and subsequent recolonization driven by Quaternary climate changes.     

A highly divergent mitochondrial DNA lineage of Microtus agrestis in southern Europe

The Mediterranean peninsulas constitute important areas for endemism and intraspecific variation, and are likely places for cryptic biodiversity. We assessed the phylogeographic pattern of field voles (Microtus agrestis) in southern and central Europe by sequence analysis of a 385-bp fragment of the mitochondrial cytochrome b gene in 74 specimens from 44 localities. The majority of samples consisted of skulls collected from owl pellets. The data revealed a highly distinct cytochrome b lineage in an area ranging from Portugal to Hungary. This southern field vole phylogroup differed by a sequence divergence of 5.6-7.1% from the remaining haplotypes, a level of divergence comparable to that found between known Microtus sibling species. However, this ancient phylogeographic break that dates back many glacial cycles has not been recognised previously by either morphology or karyotype. The southern cytochrome b lineage was further divided into two well-defined sublineages that appear to have derived from different glacial refugia in the Iberian Peninsula.     

The influence of life‐history strategy on genetic differentiation and lineage divergence in darters (Percidae: Etheostomatinae)

Recent studies determined that darters with specialized breeding strategies can exhibit deep lineage divergence over fine geographic scales without apparent physical barriers to gene flow. However, the extent to which intrinsic characteristics interact with extrinsic factors to influence population divergence and lineage diversification in darters is not well understood. This study employed comparative phylogeographic and population genetic methods to investigate the influence of life history on gene flow, dispersal ability, and lineage divergence in two sympatric sister darters with differing breeding strategies. Our results revealed highly disparate phylogeographic histories, patterns of genetic structure, and dispersal abilities between the two species suggesting that life history may contribute to lineage diversification in darters, especially by limiting dispersal among large river courses. Both species also showed striking differences in demographic history, indicating that extrinsic factors differentially affected each species during the Pleistocene. Collectively, our results indicate that intrinsic and extrinsic factors have influenced levels of gene flow among populations within both species examined. However, we suggest that life‐history strategy may play a more important role in lineage diversification in darters than previously appreciated, a finding that has potentially important implications for understanding diversification of the rich North American freshwater fish fauna.     

Has past climate change affected cold‐specialized species differentially through space and time?

Quaternary climate change has been strongly linked to distributional shifts and recent species diversification. Montane species, in particular, have experienced enhanced isolation and rapid genetic divergence during glacial fluctuations, and these processes have resulted in a disproportionate number of neo‐endemic species forming in high‐elevation habitats. In temperate montane environments, a general model of alpine population history is well supported, where cold‐specialized species track favourable climate conditions downslope during glacial episodes and upslope during warmer interglacial periods, which leads to a climate‐driven population or species diversification pump. However, it remains unclear how geography mediates distributional changes and whether certain episodes of glacial history have differentially impacted rates of diversification. We address these questions by examining phylogenomic data in a North American clade of flightless, cold‐specialized insects, the ice crawlers (Insecta: Grylloblattodea: Grylloblattidae: Grylloblatta). These low‐vagility organisms have the potential to reveal highly localized refugia and patterns of spatial recolonization, as well as a longer history of in situ diversification. Using continuous phylogeographic analysis of species groups, we show that all species tend to retreat to nearby low‐elevation habitats across western North America during episodes of glaciation, but species at high latitude exhibit larger distributional shifts. Lineage diversification was examined over the course of the Neogene and Quaternary periods, with statistical analysis supporting a direct association between climate variation and diversification rate. Major increases in lineage diversification appear to be correlated with warm and dry periods, rather than with extreme glacial events. Finally, we identify substantial cryptic diversity among ice crawlers, leading to high endemism across their range. This diversity provides new insights into highly localized glacial refugia for cold‐specialized species across western North America.     

Evidence of Sundaland’s subsidence requires revisiting its biogeography

It is widely accepted that sea level changes intermittently inundated the Sunda Shelf throughout the Pleistocene, separating Java, Sumatra and Borneo from the Malay Peninsula and from each other. On this basis, the dynamics of the biodiversity hotspot of Sundaland is consistently regarded as solely contingent on glacial sea level oscillations, with interglacial highstands creating intermittent dispersal barriers between disjunct landmasses. However, recent findings on the geomorphology of the currently submerged Sunda shelf suggest that it subsided during the Pleistocene and that, over the Late Pliocene and Quaternary, is was never submerged prior to Marine Isotope Stage 11 (MIS 11, 400 ka). This would have enabled the dispersal of terrestrial organisms regardless of sea level variations until 400 ka and hampered movements thereafter, at least during interglacial periods. Existing phylogeographic data for terrestrial organisms conform to this scenario: available divergence time estimates reveal an 8- to 9-fold increase in the rate of vicariance between landmasses of Sundaland after 400 ka, corresponding to the onset of episodic flooding of the Sunda shelf. These results highlight how reconsidering the paleogeographic setting of Sundaland challenges understanding the mechanisms generating Southeast Asian biodiversity.     

Vicariance and dispersal effects on phylogeographic structure and speciation in a widespread estuarine invertebrate

Vicariance and dispersal can strongly influence population genetic structure and allopatric speciation, but their importance in the origin of marine biodiversity is unresolved. In transitional estuarine environments, habitat discreteness and dispersal barriers could enhance divergence and provide insight to evolutionary mechanisms underlying marine and freshwater biodiversity. We examined this by assessing phylogeographic structure in the widespread amphipod Gammarus tigrinus across 13 estuaries spanning its northwest Atlantic range from Quebec to Florida. Mitochondrial cytochrome c oxidase I and nuclear internal transcribed spacer 1 phylogenies supported deep genetic structure consistent with Pliocene separation and cryptic northern and southern species. This break occurred across the Virginian-Carolinian coastal biogeographic zone, where an oceanographic discontinuity may restrict gene flow. Ten estuarine populations of the northern species occurred in four distinct clades, supportive of Pleistocene separation. Glaciation effects on genetic structure of estuarine populations are largely unknown, but analysis of molecular variance (AMOVA) supported a phylogeographic break among clades in formerly glaciated versus nonglaciated areas across Cape Cod, Massachusetts. This finding was concordant with patterns in other coastal species, though there was no significant relationship between latitude and genetic diversity. This supports Pleistocene vicariance events and divergence of clades in different northern glacial refugia. AMOVA results and private haplotypes in most populations support an allopatric distribution across estuaries. Clade mixture zones are consistent with historical colonization and human-mediated transfer. An isolation-by-distance model of divergence was detected after we excluded a suspected invasive haplotype in the St. Lawrence estuary. The occurrence of cryptic species and divergent population structure support limited dispersal, dispersed habitat distribution, and historical factors as important determinants of estuarine speciation and diversification.     

Beyond the Mediterranean peninsulas: evidence of central European glacial refugia for a temperate forest mammal species, the bank vole (Clethrionomys glareolus)

This study details the phylogeographic pattern of the bank vole, Clethrionomys glareolus, a European rodent species strongly associated with forest habitat. We used sequences of 1011 base pairs of the mitochondrial DNA cytochrome b gene from 207 bank voles collected in 62 localities spread throughout its distribution area. Our results reveal the presence of three Mediterranean (Spanish, Italian and Balkan) and three continental (western, eastern and 'Ural') phylogroups. The endemic Mediterranean phylogroups did not contribute to the post-glacial recolonization of much of the Palaearctic range of species. Instead, the major part of this region was apparently recolonized by bank voles that survived in glacial refugia in central Europe. Moreover, our phylogeographic analyses also reveal differentiated populations of bank voles in the Ural mountains and elsewhere, which carry the mitochondrial DNA of another related vole species, the ruddy vole (Clethrionomys rutilus). In conclusion, this study demonstrates a complex phylogeographic history for a forest species in Europe which is sufficiently adaptable that, facing climate change, survives in relict southern and northern habitats. The high level of genetic diversity characterizing vole populations from parts of central Europe also highlights the importance of such regions as a source of intraspecific genetic biodiversity.     

Multilocus phylogeography of the flightless darkling beetle Nyctoporis carinata (Coleoptera: Tenebrionidae) in the California Floristic Province: deciphering an evolutionary mosaic

The California Floristic Province (CFP) is considered a global biodiversity hotspot because of its confluence of high species diversity across a wide range of threatened habitats. To understand how biodiversity hotspots such as the CFP maintain and generate diversity, we conducted a phylogeographic analysis of the flightless darkling beetle, Nyctoporis carinata, using multiple genetic markers. Analyses of both nuclear and mitochondrial loci revealed an east–west genetic break through the Transverse Ranges and high genetic diversity and isolation of the southern Sierra Nevada Mountains. Overall, the results obtained suggest that this species has a deep evolutionary history whose current distribution resulted from migration out of a glacial refugium in the southern Sierra Nevada via the Transverse Ranges. This finding is discussed in light of similar genetic patterns found in other taxa to develop a foundation for understanding the biodiversity patterns of this dynamic area. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 99 , 424–444.     

Phylogeography of Silver Pheasant (Lophura nycthemera L.) across China: aggregate effects of refugia,introgression and riverine barriers

The role of Pleistocene glacial cycles in forming the contemporary genetic structure of organisms has been well studied in China with a particular focus on the Tibetan Plateau. However, China has a complex topography and diversity of local climates, and how glacial cycles may have shaped the subtropical and tropical biota of the region remains mostly unaddressed. To investigate the factors that affected the phylogeography and population history of a widely distributed and nondeciduous forest species, we analysed morphological characters, mitochondrial DNA sequences and nuclear microsatellite loci in the Silver Pheasant (Lophura nycthemera). In a pattern generally consistent with phenotypic clusters, but not nominal subspecies, deeply divergent mitochondrial lineages restricted to different geographic regions were detected. Coalescent simulations indicated that the time of main divergence events corresponded to major glacial periods in the Pleistocene and gene flow was only partially lowered by drainage barriers between some populations. Intraspecific cytonuclear discordance was revealed in mitochondrial lineages from Hainan Island and the Sichuan Basin with evidence of nuclear gene flow from neighbouring populations into the latter. Unexpectedly, hybridization was revealed in Yingjiang between the Silver Pheasant and Kalij Pheasant (Lophura leucomelanos) with wide genetic introgression at both the mtDNA and nuclear levels. Our results highlight a novel phylogeographic pattern in a subtropical area generated from the combined effects of climate oscillation, partial drainage barriers and interspecific hybridization. Cytonuclear discordance combined with morphological differentiation implies that complex historical factors shaped the divergence process in this biodiversity hot spot area of southern China.     

Speciation in an avian complex endemic to the mountains of Middle America (Ergaticus, Aves: Parulidae)

The implementation of the phylogeographic approach for the study of biodiversity is critical in poorly sampled regions like the montane systems of Middle America, as complex evolutionary histories often result in the presence of independent lineages not properly considered by traditional taxonomy. Herein we sequenced 2370 bp of mtDNA (ND2, cyt b and ATPase) from 81 individuals of Ergaticus, a complex of birds endemic to the montane forests of Middle America. Although current taxonomy recognizes two species, the results reveal considerable genetic structure with the presence of four mtDNA lineages. Two of these lineages within Ergaticus ruber evidence the need of a revaluation of the species limits for this taxon. The general phylogeographic pattern can be explained as a consequence of relative isolation of the populations in different mountain ranges separated by low elevation barriers. Most population groups did not show signals of demographic expansion with the exception of the one corresponding to clade 1. The divergence time estimates point to the Pleistocene as an important time period for the diversification of this complex.     

Untangling the evolutionary history of a highly polymorphic species: introgressive hybridization and high genetic structure in the desert cichlid fish Herichtys minckleyi

Understanding the origin of biodiversity requires knowledge on the evolutionary processes that drive divergence and speciation, as well as on the processes constraining it. Intraspecific polymorphisms can provide insight into the mechanisms that generate and maintain phenotypic, behavioural and life history diversification, and can help us understand not only the processes that lead to speciation but also the processes that prevent local fixation of morphs. The ‘desert cichlid’ Herichtys minckleyi is a highly polymorphic species endemic to a biodiversity hotspot in northern Mexico, the Cuatro Ciénegas valley. This species is polymorphic in body shape and trophic apparatus, and eco‐morphotypes coexist in small spring‐fed lagoons across the valley. We investigated the genetic structure of these polymorphisms and their phylogeographic history by analysing the entire control region of the mitochondrial DNA and 10 nuclear microsatellite markers in several populations from different sites and morphs. We found two very divergent mitochondrial lineages that most likely predate the closing of the valley and are not associated with morphotypes or sites. One of these lineages is also found in the sister species Herichthys cyanoguttatus. Data from neutral microsatellite markers suggest that most lagoons or drainages constitute their own genetic cluster with sympatric eco‐morphotypes forming panmictic populations. Alternative mechanisms such as phenotypic plasticity and a few loci controlled traits provide possible explanations for the sympatric coexistence of discrete nonoverlapping eco‐morphotypes with apparent lack of barriers to gene flow within multiple lagoons and drainages.     

REVISITING WALLACE'S HAUNT: COALESCENT SIMULATIONS AND COMPARATIVE NICHE MODELING REVEAL HISTORICAL MECHANISMS THAT PROMOTED AVIAN POPULATION DIVERGENCE IN THE MALAY ARCHIPELAGO

Sundaland, a biogeographic region of Southeast Asia, is a major biodiversity hotspot. However, little is known about the relative importance of Pleistocene habitat barriers and rivers in structuring populations and promoting diversification here. We sampled 16 lowland rainforest bird species primarily from peninsular Malaysia and Borneo to test the long‐standing hypothesis that animals on different Sundaic landmasses intermixed extensively when lower sea‐levels during the Last Glacial Maximum (LGM) exposed land‐bridges. This hypothesis was rejected in all but five species through coalescent simulations. Furthermore, we detected a range of phylogeographic patterns; Bornean populations are often genetically distinct from each other, despite their current habitat connectivity. Environmental niche modeling showed that the presence of unsuitable habitats between western and eastern Sundaland during the LGM coincided with deeper interpopulation genetic divergences. The location of this habitat barrier had been hypothesized previously based on other evidence. Paleo‐riverine barriers are unlikely to have produced such a pattern, but we cannot rule out that they acted with habitat changes to impede population exchanges across the Sunda shelf. The distinctiveness of northeastern Borneo populations may be underlied by a combination of factors such as rivers, LGM expansion of montane forests and other aspects of regional physiography.     

Multigenic and morphometric differentiation of ground squirrels (Spermophilus, Scuiridae, Rodentia) in Turkey, with a description of a new species

This study reports on the molecular phylogenetics of ground squirrels, genus Spermophilus, in Turkey using cytochrome b (1140bp), part of the D-loop and flanking tRNAs (572bp), X chromosome (867-1051bp) and Y chromosome (983-989bp) DNA sequences. Individuals also were characterized by karyotype and with geometric morphometric analyses of mandibles and skulls. Two hundred fourteen individuals from 91 localities were studied. All the data support the recognition of a new species in SW Anatolia: the Taurus ground squirrel Spermophilus taurensis sp. nov. The new species has a small distribution in the Taurus Mountains in an area that is a hotspot for biodiversity. Molecular clock analysis suggests that the new species diverged from the European ground squirrel, Spermophilus citellus, about 2.5 million years ago and that the ancestor of these two species diverged from the widespread Anatolian ground squirrel, Spermophilus xanthoprymnus, about 5 million years ago. Morphometric differentiation in skull and mandible shape among the three species is incomplete, but statistically significant. S. xanthoprymnus is subdivided into five cytochrome b phylogroups and we use these data to infer the location of glacial refugia where the species lived during the last glacial maximum. This study illustrates the potential of combined molecular and morphometric studies to uncover new Anatolian species and to reconstruct their phylogeographic history. The new species is important for squirrel taxonomy and for understanding Eurasian mammal evolution.     

Winter is coming: Miocene and Quaternary climatic shifts shaped the diversification of Western‐Mediterranean Harpactocrates (Araneae,Dysderidae) spiders

Past climatic shifts have played a major role in generating and shaping biodiversity. Quaternary glacial cycles are the better known examples of dramatic climatic changes endured by ecosystems in temperate regions. Although still a matter of debate, some authors suggest that glaciations promoted speciation. Here we investigate the effect of past climatic changes on the diversification of the ground‐dwelling spider genus Harpactocrates, distributed across the major mountain ranges of the western Mediterranean. Concatenated and species‐tree analyses of multiple mitochondrial and nuclear loci, combined with the use of fossil and biogeographic calibration points, reveal a Miocene origin of most nominal species, but also unravel several cryptic lineages tracing back to the Pleistocene. We hypothesize that the Miocene Climatic Transition triggered major extinction events in the genus but also promoted its subsequent diversification. Under this scenario, the Iberian mountains acted as an island‐like system, providing shelter to Harpactocrates lineages during the climate shifts and favouring isolation between mountain ranges. Quaternary glacial cycles contributed further to the diversification of the group by isolating lineages in peripheral refugia within mountain ranges. In addition, we recovered some unique biogeographic patterns, such as the colonization of the Alps and the Apennines from the Iberian Peninsula.     

Evidence of a highly complex phylogeographic structure on a specialist river bird species, the dipper (Cinclus cinclus)

This study details the phylogeographic pattern of the white-throated dipper (Cinclus cinclus), a Palearctic, temperate, passerine bird that is exclusively associated with flowing water. Our results reveal a complex phylogeographic structure with at least five distinct lineages for the Western Palearctic region. As for many species of the Western Palearctic fauna and flora, this genetic structure is probably linked to the isolation of populations in different southern refuges during glacial periods. Furthermore, the isolation of populations in Scandinavia and/or Eastern regions, but also in Morocco and probably in Corsica, was accentuated by ecological and biogeographic barriers during Quaternary interglacial periods. During glacial periods, Italy, Sicily and the Balkano-Carpathian region acted as major refuge zones for the dipper. At the end of the last ice age, Western Europe was repopulated by dippers from an Italian refuge, while Eastern Europe was recolonised by Balkano-Carpathian birds. A large contact zone between these two lineages was evidenced and extends from Luxembourg to Hungary. Finally, our results indicate the need to clarify the taxonomic status of the dipper, especially concerning the European subspecies whose validity appears uncertain.     

Stop and Go – Waves of Tarsier Dispersal Mirror the Genesis of Sulawesi Island

The Indonesian island of Sulawesi harbors a highly endemic and diverse fauna sparking fascination since long before Wallace’s contemplation of biogeographical patterns in the region. Allopatric diversification driven by geological or climatic processes has been identified as the main mechanism shaping present faunal distribution on the island. There is both consensus and conflict among range patterns of terrestrial species pointing to the different effects of vicariant events on once co-distributed taxa. Tarsiers, small nocturnal primates with possible evidence of an Eocene fossil record on the Asian mainland, are at present exclusively found in insular Southeast Asia. Sulawesi is hotspot of tarsier diversity, whereby island colonization and subsequent radiation of this old endemic primate lineage remained largely enigmatic. To resolve the phylogeographic history of Sulawesi tarsiers we analyzed an island-wide sample for a set of five approved autosomal phylogenetic markers (ABCA1, ADORA3, AXIN1, RAG1, and TTR) and the paternally inherited SRY gene. We constructed ML and Bayesian phylogenetic trees and estimated divergence times between tarsier populations. We found that their arrival at the Proto-Sulawesi archipelago coincided with initial Miocene tectonic uplift and hypothesize that tarsiers dispersed over the region in distinct waves. Intra-island diversification was spurred by land emergence and a rapid succession of glacial cycles during the Plio-Pleistocene. Some tarsier range boundaries concur with spatial limits in other taxa backing the notion of centers of faunal endemism on Sulawesi. This congruence, however, has partially been superimposed by taxon-specific dispersal patterns.