An official website of the United States government
ABSTRACT AimWe assess the systematic relationships and historical biogeographic patterns in the subfamily Scincinae, a group of lizards that primarily inhabits the Afro‐Madagascan and Saharo‐Arabian regions with isolated lineages in Europe, North America, East Asia, India and Sri Lanka. The contemporary distribution of these lineages on the historical Laurasian and Gondwanan landmasses make scincines an ideal system to study the roles of vicariance and dispersal on a geologic scale of tens of millions of years. LocationGlobal. TaxonSubfamily Scincinae (Family Scincidae). MethodsWe conducted biogeographic analyses on a reconstructed, time‐calibrated species tree of scincine genera, including members of the other Scincidae subfamilies, using seven nuclear loci (~6 k base pairs). We also constructed a lineage‐through‐time plot to assess the timing of diversification within scincines. ResultsOur analysis estimated strong support for the monophyly of Scincinae that is further comprised a strongly‐supported Gondwanan clade nested within a broader Laurasian group. While most of the extant, genus‐level diversity within the Gondwanan clade was accrued post‐Eocene, the majority of the Laurasian lineages diverged during the Palaeocene or earlier, suggesting large‐scale extinctions on continents of Laurasian origin. Counterintuitively, scincines from India and Sri Lanka have distinct biogeographical origins despite a long tectonic association between these landmasses, suggesting at least two independent, long‐distance, trans‐oceanic dispersal events into the subcontinent. Our biogeographic analyses suggest that scincines likely originated in East and Southeast Asia during the late Cretaceous (ca. 70 Ma), and eventually dispersed westwards to Africa and Madagascar, where their greatest current‐day species richness occurs. Main ConclusionsOur study demonstrates the concomitant roles of dispersal and extinction in shaping modern‐day assemblages of ancient clades such as scincine lizards. Our range evolution analysis shows that despite the greater diversity observed in the Afro‐Madagascan region, the origin of scincines can be traced back to Southeast Asia and East Asia, followed by westward dispersals. These dispersals may have been followed by significant extinctions in tropical East Asia, resulting in relatively lower diversity of scincines in these regions. Notably, our analysis reveals that Sri Lankan and Peninsular Indian scincines have distinct evolutionary origins.
more »
« less
Out of Africa? A dated molecular phylogeny of the cicada tribe Platypleurini Schmidt (Hemiptera: Cicadidae), with a focus on African genera and the genus Platypleura Amyot & Audinet‐Serville
Abstract The Platypleurini is a large group of charismatic cicadas distributed from Cape Agulhas in South Africa, through tropical Africa, Madagascar, India and eastern Asia to Japan, with generic diversity concentrated in equatorial and southern Africa. This distribution suggests the possibility of a Gondwanan origin and dispersal to eastern Asia from Africa or India. We used a four‐gene (three mitochondrial) molecular dataset, fossil calibrations and molecular clock information to explore the phylogenetic relationships of the platypleurine cicadas and the timing and geography of their diversification. The earliest splits in the tribe were found to separate forest genera in Madagascar and equatorial Africa from the main radiation, and all of the Asian/Indian species sampled formed a younger clade nested well within the African taxa. The tribe appears to have diversified during the Cenozoic, beginningc. 50–32 Ma, with most extant African lineages originating in the Miocene or later, well after the breakup of the Gondwanan landmass. Biogeographical analysis suggests an African origin for the tribe and a single dispersal event founding the Asian platypleurines, although additional taxon sampling and genetic data will be needed to confirm this pattern because key nodes in the tree are still weakly supported. Two Platypleurini genera from Madagascar (PycnaAmyot & Audinet‐Serville,YangaDistant) are found to have originated by late Miocene dispersal of a single lineage from Africa. The genusPlatypleurais recovered as polyphyletic, withPlatypleura signiferaWalker from South Africa and many Asian/Indian species apparently requiring assignment to different genera, and a newPlatypleuraconcept is proposed with the synonymization ofAzanicadaVilletsyn.n.The generaOrapaDistant andHamzaDistant, currently listed within separate tribes but suspected of platypleurine affinity, are nested deeply within the Platypleurini radiation. The tribe Orapinisyn.n. is here synonymized while the tribe Hamzini is pending a decision of the ICZN to preserve nomenclatorial stability.
more »
« less
- Award ID(s):
- 1655891
- PAR ID:
- 10371392
- Publisher / Repository:
- Wiley-Blackwell
- Date Published:
- Journal Name:
- Systematic Entomology
- Volume:
- 44
- Issue:
- 4
- ISSN:
- 0307-6970
- Format(s):
- Medium: X Size: p. 842-861
- Size(s):
- p. 842-861
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
null (Ed.)Abstract The ‘Out of India’ hypothesis is often invoked to explain patterns of distribution among Southeast Asian taxa. According to this hypothesis, Southeast Asian taxa originated in Gondwana, diverged from their Gondwanan relatives when the Indian subcontinent rifted from Gondwana in the Late Jurassic, and colonized Southeast Asia when it collided with Eurasia in the early Cenozoic. A growing body of evidence suggests these events were far more complex than previously understood, however. The first quantitative reconstruction of the biogeography of Asian forest scorpions (Scorpionidae Latreille, 1802: Heterometrinae Simon, 1879) is presented here. Divergence time estimation, ancestral range estimation, and diversification analyses are used to determine the origins, dispersal and diversification patterns of these scorpions, providing a timeline for their biogeographical history that can be summarized into four major events. (1) Heterometrinae diverged from other Scorpionidae on the African continent after the Indian subcontinent became separated in the Cretaceous. (2) Environmental stresses during the Cretaceous–Tertiary (KT) mass extinction caused range contraction, restricting one clade of Heterometrinae to refugia in southern India (the Western Ghats) and Sri Lanka (the Central Highlands). (3) Heterometrinae dispersed to Southeast Asia three times during India’s collision with Eurasia, the first dispersal event occurring as the Indian subcontinent brushed up against the western side of Sumatra, and the other two events occurring as India moved closer to Eurasia. (4) Indian Heterometrinae, confined to southern India and Sri Lanka during the KT mass extinction, recolonized the Deccan Plateau and northern India, diversifying into new, more arid habitats after environmental conditions stabilized. These hypotheses, which are congruent with the geological literature and biogeographical analyses of other taxa from South and Southeast Asia, contribute to an improved understanding of the dispersal and diversification patterns of taxa in this biodiverse and geologically complex region.more » « less
-
Abstract Many insect groups have acquired obligate microbial symbionts, and the resulting associations can have important ecological and evolutionary consequences. A notable example among ants is the species‐rich tribe Camponotini, whose members derive nutritional benefits from a vertically inherited bacterial endosymbiont,Blochmannia. We generate ultraconserved element (UCE) phylogenomic data for 220 ingroup and 5 outgroup taxa to reconstruct a detailed evolutionary history of the Camponotini, including the inference of divergence times and dispersal events. Under multiple modes of analysis, including both concatenation and species‐tree approaches, we recover a well‐supported backbone phylogeny comprising eight lineages: three large genera (Camponotus,Colobopsis,Polyrhachis) and several smaller genera or clusters of genera. Three novel lineages are uncovered that cannot be placed in any existing genus:Lathidrisgen. n., from the mountains of Mesoamerica;Retalimyrmagen. n., from the Indian Himalayas; andUwarigen. n., from eastern Asia. The species in these new genera were described and placed erroneously inCamponotus. The tribe Camponotini is estimated to have a crown origin in the Eocene (median age 38.4 Ma), with successively younger crown ages forColobopsis(22.5 Ma),Camponotus(18.6 Ma) andPolyrhachis(18.5 Ma). We infer an Australasian or Indomalayan origin for the tribe, with multiple dispersal events to the Afrotropics, Palearctic region, and New World. Phylogenetic analysis of selectedBlochmanniagenes from a subset of 97 camponotine taxa yields results that are largely congruent with the ant host phylogeny, at least for well‐supported nodes, but we find evidence thatBlochmanniafrom some old lineages—especiallyLathidris—may have discordant histories, suggesting possible lability of this symbiosis in the early evolution of camponotine ants.more » « less
-
The cicadas (Hemiptera: Cicadidae) related to tribe Cicadini exhibit some of the most remarkable phenotypes in the family, with many genera possessing striking colour patterns and unusual morphological features. This largely Asian group of 13 tribes has proven challenging for cicada taxonomists, in part because of likely convergent evolution or losses of these phenotypes. We present the first focused molecular phylogeny of this clade, including ~60 described genera. The genetic dataset contains 839 ingroup-informative sites (out of 2575) from mitochondrial cytochrome c oxidase subunit I, nuclear elongation factor-1 α, and nuclear acetyltransferase. We use Bayesian and maximum likelihood trees to test recent changes in tribe- and subtribe-level classification, and we reconstruct ancestral character states for potentially convergent traits influencing tribe descriptions. We use fossil and molecular clock calibrations to estimate the temporal and geographic context of the radiation. The tribes Gaeanini, Leptopsaltriini, Platypleurini, Psithyristriini, and Tosenini appear polyphyletic and in need of revision, in part because of convergent evolution of opaque wings and multiple convergent gains or losses of abdominal tubercles. Kalabita Moulton, 1923 is transferred from Platypleurini to Leptopsaltriini. Vittagaeana gen. nov. is established for Vittagaeana paviei comb. nov. and Vittagaeana dives comb. nov., formerly in Tosena. Sinosenini syn. nov. is synonymised with Dundubiina. Ayuthiini trib. nov. is established with two new subtribes for Ayuthia Distant, 1919 and Distantalna Boulard, 2009, formerly in Tosenini. For the earliest split in the tree, one common ancestor appears to have been Indian + Asian in geographic distribution and the other Asian. We estimate that the radiation began in the middle Cenozoic Era, possibly as recently as the early Miocene. The recent and steady pattern of diversification suggests that refinement of tribe diagnoses will prove challenging.more » « less
-
Recently discovered Ypresian-age amber from Cambay, India, reveals an ancient arthropod assemblage on the Indian subcontinent during its collision with Asia. Despite the tectonic history of India, limited connections have been found between the Cambay palaeofauna and present-day Madagascan and mainland African faunas. Here, I describe a new fossil pselaphine rove beetle (Staphylinidae: Pselaphinae) recovered from the Cambay deposit that shows closest apparent phylogenetic affinity to modern Afrotropical genera. Yprezethinus grimaldii gen. et sp. nov. is placed in Bythinoplectini, subtribe Bythinoplectina. Based on antennal and maxillary palp morphology, Yprezethinus is a putative transitional stem lineage of the Zethinus-group of genera—an extant clade distributed across equatorial African rainforests. Although Yprezethinus shares with this clade the derived feature of ovoid antennal clubs formed by tight appression of the apical two segments, it differs from its putative extant relatives in its possession of the plesiomorphic complement of 11 antennomeres, without any fusions of segments. The fossil taxon signifies a biotic link between early Eocene India and continental Africa, and marks the Cenozoic emergence of a tropical leaf litter arthropod fauna approaching that of contemporary, ant-dominated rainforests.more » « less
