Molecular phylogeny and historical biogeography of the genus Platycerus (Coleoptera,Lucanidae) in East Asia

The genus Platycerus is a cool temperature zone taxon widely distributed in the Northern Hemisphere. In East Asia, 10, one and 28 species are known in Japan, Korea and China, respectively. Recent studies of Platycerus have revealed the divergence pattern in Japan and South Korea, but that of Chinese Platycerus is unknown. We conducted a phylogenetic and biogeographical study of Platycerus in East Asia, including China, using 68, 87 and 296 sequence data of the nuclear wingless gene, internal transcribed spacer (ITS) region and mitochondrial COI gene, respectively. Although the introgression of mitochondrial genes had been known in Japanese Platycerus, the essential contradiction was not recognized between the phylogenetic trees of nuclear genes and COI in Chinese Platycerus. In the COI tree, the Japanese clade and Asian continental clade diverged around 10.84 million years ago, and four major clades were recognized in the latter. For the shape of the posterolateral corner of the Platycerus pronotum, sharp (S)-type species are distributed in higher latitudinal and lower altitudinal areas than round (R)-type species in the Asian continent. S-type species have evolved from R-type species at least three times in more northerly areas, where the annual amplitude of temperature change is large. The genus Platycerus has been differentiated and speciated by a process unique to South Korea, Japan and China, according to regional topography. Thus, genetic differentiation and speciation in Platycerus are related to latitudinal and altitudinal gradients, as well as the site topographical profile and niche differentiation.     

Molecular phylogeny and biogeography of the grass lizards genus Takydromus (Reptilia: Lacertidae) of East Asia

Takydromus Daudin is a group of Lacertidae lizards with slender bodies and long tails. Half of the Takydromus spp. are endemic to islands of eastern Asia aligned along the Pacific margin of the East Asian continent. This feature offers a good opportunity to study the effects of glaciations and land connections on the speciation of East Asian fauna. We reconstructed the molecular phylogeny of Takydromus species via the mitochondrial 12S rRNA gene. Phylogenetic analyses using maximum-parsimony, neighbor-joining, and maximum-likelihood options do not support a two-subgenera scheme of Takydromus and Platyplacopus proposed earlier. In contrast, the phylogeny of Takydromus species on islands fits the sequential separation of island groups influenced by changes in sea level. The hypothesis in our prediction supports the process of vicariant speciation and multicolonization of grass lizards on eastern Asian islands. At least two obvious colonization events were followed by vicariance events. Because the molecular clock of the 12 rRNA gene was not rejected in our model test, it is possible to estimate times of speciation events. As the most isolated and basal species compared to other temperate and subtropical species of Takydromus, the separation period of T. smaragdinus in the central Ryukyus is the crucial point in estimating the evolutionary rate. Quaternary-origin or Tertiary-origin models are proposed and discussed.     

Mitochondrial phylogeny and biogeography of the genus Gobio (Teleostei: Cyprinidae) in Turkey

Species of the cyprinid genus Gobio Cuvier, 1816 are widely distributed in freshwater lakes and rivers in Turkey, which is a hotspot for freshwater fish diversity and endemism. The mitochondrial 16S, coxI and cytb genes were sequenced for 217 individuals representing 15 species of Gobio from Turkey. A total of 23 haplotypes were identified for each mitochondrial gene. The genetic distance matrices show that Turkish Gobio species are clustered into three groups (northwestern, central and northeastern Anatolia). Phylogenetic trees constructed with combined dataset by using maximum parsimony, maximum likelihood and Bayesian inference methods revealed that the Turkish Gobio species belongs to three well-supported groups in accordance with their geographic distribution: Group I comprises species found in Central Anatolia, Group II species ranging from eastern Thrace to western Anatolia (northwestern Group) and Group III contains only one species from Western Transcaucasia (northeastern Group). The estimated divergence times between the three Gobio groups, calculated using a conventional 1% rate of mutation for a fish mitochondrial cytb gene per million years, coincide with the late Miocene period in which the tectonic uplift of Anatolia and global climate fluctuations occurred. The relatively low genetic distance between Gobio species in the Turkish Lake District indicate that they are not good species.     

Mitochondrial DNA rates and biogeography in European newts (genus Euproctus)

Sequence divergence for segments of three mitochondrial DNA (mtDNA) genes encoding the 12S and 16S ribosomal RNA and cytochrome b was examined in newts belonging to the genus Euproctus (E. asper, E. montanus, E. platycephalus) and in three other species belonging to the same family (Salamandridae), Triturus carnifex, T. vulgaris, and Pleurodeles waltl. The three Euproctus species occur (one species each) in Corsica, Sardinia, and the Pyrenees. This vicariant distribution is believed to have been determined by the disjunction and rotation of the Sardinia-Corsica microplate from the Pyreneean region. Because time estimates are available for the tectonic events that led to the separation of the three landmasses, we used sequence data to estimate rates of evolution for the three gene fragments and investigated whether they conform to the rate-constancy hypothesis. By the Tajima (1993, Genetics 135:599-607) test, we could not detect rate heterogeneities for the ribosomal genes and for transversions in the cytochrome b gene. Assuming that these sites are evolving linearly over time and that cessation of gene flow occurred simultaneously with vicariant events, we compared the time of divergence estimated by molecular distances with the divergence times based on the geological estimates. Because we have two estimates of divergence time from the geological record, the split of Corsica/Sardinia from the Pyrenees and the split of Corsica from Sardinia, we could compare ratios of molecular divergence with the ratio of geological time divergence. The ratios are very similar, indicating that the molecular clock hypothesis cannot be rejected. These geological events also allowed us to calculate absolute rates of evolution for ribosomal and cytochrome b genes and compare them to rates for the same regions in other salamandrids and other vertebrates. Ribosomal mtDNA rates are comparable to those reported for other vertebrates, but cytochrome b rates are 3-7 times lower in salamanders than in other ectotherms. From a phylogenetic perspective, our data suggest that the cladogenic events leading to species formation in Euproctus and Triturus occurred very closely in time, indicating that the two genera may not be monophyletic. A duplication of the cytochrome b gene in T. carnifex was found, and the implications of this finding for mtDNA phylogenetic studies are discussed.     

Out of South‐East Asia: phylogeny and biogeography of the spiny ant genus Polyrhachis Smith (Hymenoptera: Formicidae)

Spiny ants (Polyrhachis Smith) are a hyper‐diverse genus of ants distributed throughout the Palaeotropics and the temperate zones of Australia. To investigate the evolution and biogeographic history of the group, we reconstructed their phylogeny and biogeography using molecular data from 209 taxa and seven genes. Our molecular data support the monophyly of Polyrhachis at the generic level and several of the 13 recognized subgenera, but not all are recovered as monophyletic. We found that Campomyrma Wheeler consists of two distinct clades that follow biogeographic affinities, that the boundaries of Hagiomyrma Wheeler are unclear depending on the analysis, that Myrma Billberg might be treated as one or two clades, and that Myrmhopla Forel is not monophyletic, as previously proposed. Our biogeographic ancestral range analyses suggest that the evolution of Polyrhachis originated in South‐East Asia, with an age of the modern crown‐group Polyrhachis of 58 Ma. Spiny ants dispersed out of South‐East Asia to Australia several times, but only once to mainland Africa around 26 Ma.     

First molecular phylogeny of the pantropical genus Dalbergia: implications for infrageneric circumscription and biogeography

The genus Dalbergia with c. 250 species has a pantropical distribution. In spite of the high economic and ecological value of the genus, it has not yet been the focus of a species level phylogenetic study. We utilized ITS nuclear sequence data and included 64 Dalbergia species representative of its entire geographic range to provide a first phylogenetic framework of the genus to evaluate previous infrageneric classifications based on morphological data. The phylogenetic analyses performed suggest that Dalbergia is monophyletic and that it probably originated in the New World. Several clades corresponding to sections of these previous classifications are revealed. Taking into account that there is not a complete correlation between geography and phylogeny, and the estimation that the Dalbergia stem and crown clades are 40.4–43.3 mya and 3.8–12.7 mya, respectively, it is plausible that several long distance dispersal events underlie the pantropical distribution of the genus.     

Mitochondrial phylogeny of notothenioids: a molecular approach to Antarctic fish evolution and biogeography

Antarctic waters represent a unique marine environment delimited by an oceanographic barrier, the Polar Front Zone, and characterized by constant subzero temperatures and presence of sea ice. A group of teleost fish, the Notothenioidei, have adapted to these challenging environmental conditions, undergoing a remarkable diversification. In the present study a total of 798 base pairs, generated from partial sequencing of 16S and 12S mitochondrial ribosomal RNA genes, were examined in 33 notothenioid species representative of all families included in the suborder Notothenioidei. Phylogenetic trees, reconstructed on the basis of sequence data by different methods, indicate that traditional hypotheses on notothenioid systematics and biogeography might be in need of reexamination. Molecular evidence suggests that vicariant speciation could be invoked to explain the early divergence of Eleginops maclovinus, a species previously included in the family Nototheniidae, which is now proposed as the closest sister group to all the rest of notothenioids apart from bovichtids. On the other hand, repeated, independent dispersal through the Polar Front is proposed for the divergence of other subantarctic notothenioid species. Likewise, multiple, independent transitions from benthic to pelagic habit are inferred from molecular data, at variance with the more conservative hypothesis based on cladograms reconstructed from morphological data.     

Mitochondrial DNA diversity and population differentiation in southern East Asia

Mitochondrial DNA (mtDNA) polymorphism has been studied systematically in the Han, Tibeto-Buman, and Hmong-Mien ethnic families of southern East Asia. Only two families in this region, Daic and Austro-Asiatic, were still uninvestigated. Daic is a major ethnic family in South China and Southeast Asia and has a long history. To study mtDNA polymorphism within this family, all the Daic populations of China and some of Vietnam (774 individuals from 30 populations) were typed by HVS-1 region sequencing and by PCR-RFLP assays. The observed high Southern type frequencies (B, F, M7, R) confirmed Daic as a typical Southern group. mtDNAs of other populations (126 individuals from 14 populations) from Austro-Asiatic ethnic families neighboring the Daic were also typed. Networks of mtDNA haplogroups in South China were traced from these new data and those from the literature. Ethnic families share many haplogroups, indicating their common origin. However, the two largest families in South China, Daic, and Hmong-Mien, polarized into several ethnic family specific haplogroups. Haplogroup ages were estimated in the networks of high-frequency haplogroups (B, F, M7, R), and they were found to originate about 50,000 years ago. In contrast, ethnic family specific haplogroups all originated around 20,000 years ago. We therefore conclude that modern humans have lived in South China for a long time, inside-ethnogenesis was a rather late event, and frequent inmixing was taking place throughout. MtDNA data of Daic, Austro-Asiatic and other populations in South China has therefore proven pivotal for studying the human history of East Asia.     

Molecular phylogeny and historical biogeography of the genus Tuber, the 'true truffles'

Aim Various data sets and methods of analysis were combined to produce the first comprehensive molecular phylogeny of the genus Tuber and to analyse its biogeography. Location Europe, North Africa, China, Asia, North America. Methods Phylogenetic relationships among Tuber species were reconstructed based on a data set of internal‐transcribed spacer (ITS) sequences and various phylogenetic inference methods, specifically maximum parsimony, Bayesian analysis and neighbour joining. Tajima’s relative rate test showed that Tuber 18S rRNA, 5.8S rRNA, 5.8S‐ITS2 rRNA and β‐tubulin sequences evolved in a clock‐like manner. These genes, combined or not, were employed for molecular clock estimates after construction of linearized trees using mega 3.1. We reconstructed ancestral areas in the Northern Hemisphere by means of a dispersal–vicariance analysis (diva 1.1) based on current distribution patterns of the genus Tuber determined from the literature. Results The resulting molecular phylogeny divided the genus Tuber into five distinct clades, in agreement with our previously published studies. The Puberulum, Melanosporum and Rufum groups were diversified in terms of species and geographical distribution. In contrast, the Aestivum and Excavatum groups were less diversified and were located only in Europe or North Africa. Using a global molecular clock analysis, we estimated the divergence times for the origin of the genus and for the origin of several groups. diva inferred nine dispersal events and suggested that the ancestor of Tuber was originally present in Europe or was widespread in Eurasia. Equally optimal distributions were obtained for several nodes, suggesting different possible biogeographical patterns. Main conclusions Our analyses identified several discrepancies with the classical taxonomy of the genus, and we propose a new phylogenetic classification. According to molecular clocks, the radiation of the genus Tuber could have started between 271 and 140 Ma. Used in combination with the results obtained from time divergence estimates, this allows us to propose two equally probable scenarios of intra‐ and inter‐continental diversification of the genus according to the geographic distribution of the most recent common ancestor in Europe or Eurasia. The biogeographical patterns imply intra‐continental dispersal events between Europe and Asia and inter‐continental dispersal events between North America and Europe or Asia, which are compatible with land connections during the Tertiary.     

Molecular phylogeny and biogeography of Malagasy frogs of the genus Gephyromantis

The genus Gephyromantis is a clade within the Malagasy-Comoroan family Mantellidae composed of rainforest frogs that live and breed to varying degrees independently from water. Based on DNA sequences of five mitochondrial and five nuclear genes we inferred the phylogeny of these frogs with full taxon coverage at the species level. Our preferred consensus tree from a partitioned Bayesian analysis of 5843 base pairs of 51 nominal and candidate species supports various major clades within the genus although the basal relationships among these remain unresolved. The data provide strong evidence for the monophyly of the subgenera Gephyromantis (after exclusion of Gephyromantis klemmeri), Laurentomantis, Vatomantis, and Phylacomantis. Species assigned to the subgenus Duboimantis belong to two strongly supported clades of uncertain relationships. G. klemmeri, previously in the subgenus Gephyromantis, was placed with high support sister to the Laurentomantis clade, and the Laurentomantis + G. klemmeri clade was sister to Vatomantis. A reconstruction of ancestral distribution areas indicates a diversification of several subgenera in the northern biogeographic regions of Madagascar and the dispersal out of northern Madagascar for several clades.     

Mitochondrial phylogeny of African wood mice, genus Hylomyscus (Rodentia, Muridae): implications for their taxonomy and biogeography

This paper investigates the usefulness of two mitochondrial genes (16S rRNA and cytochrome b) to solve taxonomical difficulties within the genus Hylomyscus and to infer its evolutionary history. Both genes proved to be suitable molecular markers for diagnosis of Hylomyscus species. Nevertheless the resolving powers of these two genes differ, and with both markers (either analyzed singly or in combination), some nodes remain unresolved. This is probably related to the fact that the species emerged during a rapid diversification event that occurred 2-6 Myr ago (4-5 Myr ago for most divergence events). Our molecular data support the recognition of an "aeta" group, while the "alleni" and "parvus" groups are not fully supported. Based on tree topology and genetic divergence, two taxa generally recognized as subspecies should be elevated at the species level (H. simus and H. cf kaimosae). H. stella populations exhibit ancient haplotype segregation that may represent currently unrecognized allopatric species. The existence of cryptic species within H. parvus is questioned. Finally, three potentially new species may occur in West Central Africa. The Congo and Oubangui Rivers, as well as the Volta and Niger Rivers and/or the Dahomey gap could have formed effective barriers to Hylomyscus species dispersal, favoring their speciation in allopatry. The pronounced shifts in African climate during the late Pliocene and Miocene, which resulted in major changes in the distribution and composition of the vegetation, could have promoted speciation within the genus (refuge theory). Future reports should focus on the geographic distribution of Hylomyscus species in order to get a better understanding of the evolutionary history of the genus.     

Systematics and biogeography of the shrike-babblers (Pteruthius): species limits, molecular phylogenetics, and diversification patterns across southern Asia

Patterns of avian diversification in southern Asia are poorly understood due to the limited number of phylogenetic and biogeographic studies of endemic groups, mainly due to the dearth of recent tissue samples and a historical taxonomic bias underestimating avifaunal diversity. A systematic analysis of the endemic genus Pteruthius, the shrike-babblers, was undertaken in order to identify basal diagnosable taxa, analyze their phylogenetic relationships, and uncover patterns of diversification within southern Asia. Traditionally considered to be 5 species, a total of 19 distinct taxa of Pteruthius are diagnosable by fixed characters under the phylogenetic species concept-almost a four-fold increase in recognized diversity. Molecular phylogenetic analyses (85% of samples were from museum specimens) recovered a robust phylogeny that was largely congruent using parsimony, likelihood, and bayesian. Initial divergences in each major clade occurred in the early to mid-Pliocene, while the remaining majority of diversification events occurred in the Pleistocene. Within Pteruthius, timings of species divergences across similar geographic regions correspond to both single and multiple Earth history events, illustrating the complexities of continental diversification. A novel biogeographic pattern of species in peripheral areas (Java, W Himalayas, S Vietnam, Assam/Burma) diverging first from those in the core-mainland areas (E Himalayas, Yunnan, N Thailand, Indochina, Malay Peninsula) was uncovered.     

Molecular probes of phylogeny and biogeography in toads of the widespread genus Bufo

Genetic relationships among 25 species of Central and South American Bufo and among representative North, Central, and South American, Asian, and African Bufo were probed, using the quantitative immunological technique of microcomplement fixation (MC'F) which indicated a clear separation of North, Central, and South American lineages of Bufo. The South American lineage likely diverged from the Central and North American lineages in the Eocene; the latter two lineages diverged later, probably in the mid-Oligocene. Some species groups of South American toads, defined on the basis of traditional morphological studies, are genetically quite similar within groups, whereas others are genetically divergent. The amount of albumin evolution does not appear to parallel the amount of karyotypic, morphological, ecological, or behavioral evolution documented. Comparisons suggest that the African lineages separated from the American and Asian lineages in the late Cretaceous, corresponding to the time of the final separation of Gondwanaland, the southern supercontinent including the modern continents of South America, Africa, Australia, Antarctica, and India. The Asian lineages diverged from the lineage giving rise to all of the American species in the early Paleocene.      

Origin, diversification, and historical biogeography of the genus Trachurus (Perciformes: Carangidae)

We addressed phylogenetic relationships in the genus Trachurus using cytochrome b gene and D-loop sequences. The trees showed five groups: (1) the Southwest Pacific species (T. japonicus, T. novaezelandiae, and T. declivis); (2) The Mediterranean Sea and Eastern Atlantic species (T. mediterraneus); (3) The Atlantic Ocean species (T. lathami and T. trecae); (4) Eastern Atlantic species (T. trachurus and T. capensis); and (5) a group of highly mobile pelagic species, two from the Eastern Pacific (T. symmetricus and T. murphyi) and one from the Eastern Atlantic (T. picturatus). The phylogeny based on Cyt b, supports the molecular clock hypothesis and our results agree with the reported fossil indicating that the origin of this genus occur when the Thetys Sea closed (around 18.4 MYA). In addition, a very slow neutral substitution rate is reported identified only two periods of maximum diversification: the first occurring between 18.4 and 15.0 MYA and the second between 8.4 MYA and present day.     

Molecular phylogeny and biogeography of the fern genus Pteris (Pteridaceae)

Background and Aims

Pteris (Pteridaceae), comprising over 250 species, had been thought to be a monophyletic genus until the three monotypic genera Neurocallis, Ochropteris and Platyzoma were included. However, the relationships between the type species of the genus Pteris, P. longifolia, and other species are still unknown. Furthermore, several infrageneric morphological classifications have been proposed, but are debated. To date, no worldwide phylogenetic hypothesis has been proposed for the genus, and no comprehensive biogeographical history of Pteris, crucial to understanding its cosmopolitan distribution, has been presented.

Methods

A molecular phylogeny of Pteris is presented for 135 species, based on cpDNA rbcL and matK and using maximum parsimony, maximum likelihood and Bayesian inference approaches. The inferred phylogeny was used to assess the biogeographical history of Pteris and to reconstruct the evolution of one ecological and four morphological characters commonly used for infrageneric classifications.

Key Results

The monophyly of Pteris remains uncertain, especially regarding the relationship of Pteris with Actiniopteris + Onychium and Platyzoma. Pteris comprises 11 clades supported by combinations of ecological and morphological character states, but none of the characters used in previous classifications were found to be exclusive synapomorphies. The results indicate that Pteris diversified around 47 million years ago, and when species colonized new geographical areas they generated new lineages, which are associated with morphological character transitions.

Conclusions

This first phylogeny of Pteris on a global scale and including more than half of the diversity of the genus should contribute to a new, more reliable infrageneric classification of Pteris, based not only on a few morphological characters but also on ecological traits and geographical distribution. The inferred biogeographical history highlights long-distance dispersal as a major process shaping the worldwide distribution of the species. Colonization of different niches was followed by subsequent morphological diversification. Dispersal events followed by allopatric and parapatric speciation contribute to the species diversity of Pteris.     

Mitochondrial genomics of ostariophysan fishes: perspectives on phylogeny and biogeography

Abstract Ostariophysi is the second largest superorder within Teleostei. It contains five orders: Gonorynchiformes, Cypriniformes, Characiformes, Siluriformes, and Gymnotiformes. Resolving the higher-level relationships among ostariophysan and related fishes will aid in resolving basal teleostean divergence and provide basis to historical biogeographic analysis of major freshwater fish groups. In this study, we report the complete mitochondrial (mt) DNA sequences for eleven ostariophysan fishes and the results of phylogenetic analyses including these species plus four other ostariophysan and nine non-ostariophysan teleostean fishes. Maximum likelihood and maximum parsimony analyses reconfirmed clupeiforms as the closest relatives of ostariophysans. However, gonorynchiforms were closer to clupeiforms than to otophysans (ostariophysan groups excluding gonorynchiforms), thus raising a question over the current definition of Ostariophysi. The lack of clarity in otocephalan (ostariophysans + clupeiforms) basal relationships implies that such divergence took place over a short period of time. The monophyly of cypriniforms, characiphysans (characiforms, siluriforms, and gymnotiforms), and orders or superorders outside the ostariophysans examined here were conceivably reconstructed. The phylogenetic hypothesis suggests a Pangean origin of otophysans. Within characiphysans, gymnotiforms and siluriforms have independent evolutionary origins and evolutionary histories comparable to or older than that of characiforms. This helps to explain the present geographic distribution of characiphysans.     

Molecular phylogeny and biogeography of the land snail genus Monacha (Gastropoda,Hygromiidae)

Monacha is the most species‐rich genus of the family Hygromiidae with a centre of diversity in Anatolia. On the basis of the presence or absence of accessory genital appendages, the group was subdivided into three subgenera, Monacha s. str., Paratheba and Metatheba, in the past. We used mitochondrial and nuclear DNA sequences of a representative sample of species 1) to reconstruct the phylogeny of the major lineages of Monacha, 2) to reconstruct the evolution of the accessory genital appendages, and 3) to reconstruct the biogeography of the group. Our results show that the accessory genital appendages upon which the classification of Monacha into subgenera rested so far, that is the appendicula, which is homologous to the dart sac and/or its accessory sac in other helicoid land snails, and the penis retractor muscle, were lost several times independently in different lineages of Monacha. Even among sister species, these characters were found to be variable. Thus, the typologically defined subgenera are para‐ or polyphyletic assemblages. The reconstruction of the biogeographical history indicated an origin of Monacha in Anatolia and the adjacent Caucasus region which is consistent with the observation that most other genera currently included in the subfamily Monachainae are also endemic to this region. Most major Monacha lineages remained restricted to northern Anatolia. Southern Europe was colonized by Monacha s. str., the Aegean region by Aegaeotheba subgen. n., the Crimean Peninsula by Paratheba and the Levant by Platytheba. On the basis of our phylogenetic analyses and testing of alternative hypotheses, we propose to divide Monacha into eight subgenera. We newly delimit the previously proposed subgenera Monacha s. str., Metatheba, Paratheba and Platytheba, and describe Pontotheba subgen. n., Aegaeotheba subgen. n., Trichotheba subgen. n. and Rhytidotheba subgen. n. as new subgenera.     

Mitochondrial DNA phylogeny of Brimstone butterflies (genus Gonepteryx) from the Canary Islands and Madeira

Part of the mitochondrial Cytochrome Oxidase I gene was sequenced for seven species of Gonepteryx (Pieridac) butterflies. Four of the species are island endemics inhabiting the Canary Island archipelago and Madeira. The remaining three are European and African conspecifics. Sequence data were analysed phylogenetically by maximum parsimony and maximum likelihood methods. The resulting trees were used to deduce Canarian species' ancestry, sequential inter-island colonization and systematics. They suggest African ancestry for the Canary Island taxa and a colonization pattern, within the archipelago, compatible with the geological ages of the islands and other Canarian fauna: a colonization sequence from Africa to Tenerife and Gomera, followed by Tenerife to La Palma. The molecular phylogeny indicated that there are three Canarian endemics, G. cleobule, G. palmae and G. eversi from Tenerife, La Palma and Gomera, respectively.     

Mitochondrial DNA based phylogeny of the woodpecker genera Colaptes and Piculus,and implications for the history of woodpecker diversification in South America

The woodpecker genus Colaptes (flickers) has its highest diversity in South America and the closely related genus Piculus is restricted to South and Central America. Two species of flickers occur in North America, and one species is endemic to Cuba. We conducted a Bayesian phylogenetic analysis of three mitochondrial encoded genes (cyt b, COI, 12S rRNA) and confirmed that the two genera are paraphyletic. Three species historically classified as Piculus are actually flickers. We found that the Cuban endemic C. fernandinae is the most basal species within the flickers and that the Northern Flicker is the next most basal species within the Colaptes lineage. The South American clade is most derived. The age of the South American diversification is estimated to be 3.6 MY, which is synchronous with the emergence of the Isthmus of Panama. The pattern of diversification of South American flickers is common among South American woodpeckers. Although woodpeckers have their greatest diversity in South America, we hypothesize that woodpeckers (Family Picidae) originated in Eurasia, dispersed to North America via the Bering land bridge, and multiple lineages entered South America as the Isthmus approached its final closing.     

Molecular phylogeny, character evolution, and biogeography of the grammitid fern genus Lellingeria (Polypodiaceae)

? Premise of the study: The recognition of monophyletic genera for groups that have high levels of homoplastic morphological characters and/or conflicting results obtained by different studies can be difficult. Such is the case in the grammitid ferns, a clade within the Polypodiaceae. In this study, we aim to resolve relationships among four clades of grammitid ferns, which have been previously recovered either as a polytomy or with conflicting topologies, with the goal of circumscribing monophyletic genera. ? Methods: The sampling included 89 specimens representing 61 species, and sequences were obtained for two genes (atpB and rbcL) and four intergenic spacers (atpB-rbcL, rps4-trnS, trnG-trnR, and trnL-trnF), resulting in a matrix of 5091 characters. The combined data set was analyzed using parsimony, likelihood, and Bayesian methods. Ninety-six morphological characters were optimized onto the generated trees, using the parsimony method. ? Key results: Lellingeria is composed of two main clades, the L. myosuroides and the Lellingeria s.s. clades, which together are sister to Melpomene. Sister to all three of these is a clade with two species of the polyphyletic genus Terpsichore. In the L. myosuroides clade, several dispersal events occurred between the neotropics, Africa, and the Pacific Islands, whereas Lellingeria s.s. is restricted to the neotropics, with about 60% of its diversity in the Andes. ? Conclusions: Overall, our results suggest that Lellingeria is monophyletic, with two clades that are easily characterized morphologically and biogeographically. Morphological characters describing the indument are the most important to define the clades within the ingroup. A small clade, previously considered in Terpsichore, should be recognized as a new genus.