Molecular phylogeny and the historical biogeography of the warblers of the genus Sylvia (Aves)

A molecular phylogeny based on DNA/DNA hybridization revealed that the Sylvia-Parisoma complex is monophyletic and includes three main groups of species, the “mid-European” warblers, the genus Parisoma, and the “eu-Mediterranean” Sylvia species sensu stricto. The latter can be assigned to three main clusters, a “West-Mediterranean” group, a “Central-Mediterranean group”, and an “East-Mediterranean” group. The radiation of the whole complex is much more ancient than formerly believed. It started ca 12–13 Ma ago and the ancestors of the main extant groups differentiated during the Pliocene. Only speciation events within the “eu-Mediterranean” lineages occurred during the Pleistocene. The paleoclimatical and paleoecological history of the Mediterranean region is too complicated to provide any evidence for direct relationships between past events and evolutionary steps of these taxa which did not leave any reliable fossil record. However, some major speciation events may be related to well documented climatical crises as well as paleobotanical data. The largely man-induced extension of matorrals over several millenia presumably extended the range of several species that were formerly much more restricted, which complicates reconstruction of the spatio-temporal course of speciation.     

The genus Dugesia in Australia, with its phylogenetic analysis and historical biogeography (Platyhelminthes, Tricladida, Dugesiidae)

The new species Dugesia notogaea Sluys & Kawakatsu, sp. n. is described from Queensland, Australia, representing the first record of the genus Dugesia for that continent. A phylogenetic analysis of the 68 species of Dugesia resulted in the discovery of a new apomorphy for the genus, and a cladogram showing two major phyletic groups. The distributional range of one group has a western accent, whereas that of the other group has an eastern emphasis; the ranges of these two groups overlap in Africa and the Mediterranean region. We attempt to determine the ancestral area for both the Dugesiidae and Dugesia. A scenario for the historical biogeography of the genus Dugesia is discussed. In this scenario it is presumed that the geological history of the Australasian region enabled Dugesia's from southeast Asia to colonize northern Australia. © 1998 The Norwegian Academy of Science and Letters     

A nuclear DNA phylogenetic perspective on the evolution of echolocation and historical biogeography of extant bats (chiroptera)

Bats (Order Chiroptera), the only mammals capable of powered flight and sophisticated laryngeal echolocation, represent one of the most species-rich and ubiquitous orders of mammals. However, phylogenetic relationships within this group are poorly resolved. A robust evolutionary tree of Chiroptera is essential for evaluating the phylogeny of echolocation within Chiroptera, as well as for understanding their biogeographical history. We generated 4 kb of sequence data from portions of four novel nuclear intron markers for multiple representatives of 17 of the 18 recognized extant bat families, as well as the putative bat family Miniopteridae. Three echolocation-call characters were examined by mapping them onto the combined topology: (1) high-duty cycle versus low-duty cycle, (2) high-intensity versus low-intensity call emission, and (3) oral versus nasal emission. Echolocation seems to be highly convergent, and the mapping of echolocation-call design onto our phylogeny does not appear to resolve the question of whether echolocation had a single or two origins. Fossil taxa may also provide insight into the evolution of bats; we therefore evaluate 195 morphological characters in light of our nuclear DNA phylogeny. All but 24 of the morphological characters were found to be homoplasious when mapped onto the supermatrix topology, while the remaining characters provided insufficient information to reconstruct the placement of the fossil bat taxa with respect to extant families. However, a morphological synapomorphy characterizing the Rhinolophoidea was identified and is suggestive of a separate origin of echolocation in this clade. Dispersal-Vicariance analysis together with a relaxed Bayesian clock were used to evaluate possible biogeographic scenarios that could account for the current distribution pattern of extant bat families. Africa was reconstructed as the center of origin of modern-day bat families.     

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 phylogenetics, historical biogeography, and chromosome number evolution of Portulaca (Portulacaceae)

Portulaca is the only genus in Portulacaceae and has ca. 100 species distributed worldwide, mainly in the tropics and subtropics. Molecular data place the genus as one of the closest relatives of Cactaceae, but phylogenetic relationships within Portulaca are barely known. This study samples 59 species of Portulaca, 10 infraspecific taxa, and three cultivars, including multiple samples of widespread species. The sampled taxa represent all subgenera in the classifications of von Poellnitz (1934), Legrand (1958), and Geesink (1969) and come from around the world. Nuclear ITS and chloroplast ndhF, trnT-psbD intergenic spacer, and ndhA intron DNA sequences were analyzed using maximum likelihood and Bayesian methods to produce a hypothesis of relationships within Portulaca. Divergence times were estimated using Hawaiian endemics for calibration, and biogeographical patterns were examined using a Bayes-DIVA approach. In addition, the evolution of chromosome numbers in the genus was investigated using probabilistic models. The analyses strongly support the monophyly of Portulaca, with an age of the most recent common ancestor (MRCA) of 23 Myr. Within Portulaca are two major lineages: the OL clade (comprising opposite-leaved species) distributed in Africa, Asia, and Australia, and the AL clade (comprising alternate to subopposite-leaved species), which is more widespread and originated in the New World. Sedopsis, a genus sometimes recognized as distinct from Portulaca based on a long corolla tube, is nested within the OL clade and does not merit taxonomic recognition. Samples of Portulaca grandiflora, Portulaca halimoides, and Portulaca oleracea were found to be non-monophyletic. It is hypothesized that the ancestral distribution area of Portulaca included southern hemisphere continents and Asia. The OL clade remained restricted to the Old World (except Portulaca quadrifida, a pantropical weed), while the AL clade, with a South American origin, was able to disperse multiple times to other continents. The base chromosome number for Portulaca is inferred to be x=9, although the analysis was primarily based on the available data for the AL clade. A number of chromosome number change events (polyploidization, demi-polyploidization, gain, and loss) were shown to have occurred in the genus, especially within the Oleracea clade.     

Molecular phylogeny and historical biogeography of the land snail genus Solatopupa (Pulmonata) in the peri-Tyrrhenian area

The land snail genus Solatopupa consists of six species and has a peri-Tyrrhenian distribution; most of the species have a very narrow range and all of them except one (Solatopupa cianensis, which inhabits porphyritic rocks) are strictly bound to calcareous substrates. One species (Solatopupa guidoni) is limited to Sardinia, Corsica, and Elba Island. Because the potential for dispersal of these snails is low, the insular range of this species has been traditionally related to the Oligocenic detachment of the Sardinia-Corsica microplate from the Iberian plate and its subsequent rotation towards the Italian peninsula. In this study, we used sequences of three mitochondrial and one nuclear gene to reconstruct the evolutionary history of the genus. Our phylogenetic results are consistent with the genetic relationships found using allozymes, but contrast with the phylogenetic hypotheses based on karyology and morphology. Molecular clock estimates indicate that the main cladogenetic events in the genus occurred between the middle Miocene and the middle-late Pliocene. Patterns of phylogenetic relationships and geological considerations suggest that the cladogenesis of the genus can be explained by vicariant (tectonic) processes. Our datings do not support a causal relation between the split of S. guidoni from its continental sister taxon and the initial phases of the detachment of the Corsica-Sardinia microplate from the mainland. On the contrary, time estimates coincide with the very last phase of detachment of the microplate (from 5 to 3 Myrs ago). Overall, our molecular clock estimates are in good agreement with the latest geological views on the tectonic evolution of the peri-Tyrrhenian area.     

Molecular phylogeny and historical biogeography of the large carpenter bees, genus Xylocopa (Hymenoptera: Apidae)

The biogeographical history of major groups of bees with worldwide distributions have often been explained through hypotheses based on Gondwanan vicariance or long distance dispersal events, but until recently these hypotheses have been very difficult, if not impossible, to distinguish. New fossil data, comprehensive information on Mesozoic and Cenozoic coastline positions and the availability of phylogenetically informative DNA markers now makes it feasible to test these hypotheses for some groups of bees. This paper presents historical biogeographical analyses of the genus Xylocopa Latreille, based on phylogenetic analyses of species belonging to 22 subgenera using molecular data from two nuclear genes, elongation factor‐1α (EF‐1α) and phosphoenolpyruvate carboxykinase (PEPCK), combined with previously published morphological and mitochondrial data sets. Phylogenetic analyses based on parsimony and likelihood approaches resulted in several groups of subgenera supported by high bootstrap values (>85%): an American group with the Oriental/Palaearctic subgenera Nyctomelitta and Proxylocopa as sister taxa; a geographically diverse group (Xylocopa s.l); and a group consisting of African and Oriental subgenera. The relationships among these three clades and the subgenus Perixylocopa remained unresolved. The Oriental subgenus Biluna was found to be the sister group of all other carpenter bee subgenera included in this study. Using a relaxed molecular clock calibrated using fossil carpenter bees, we show that the major splits in the carpenter bee phylogeny occurred well after the final breakup of Gondwanaland (the separation of South America and Africa, 100 Mya), but before important Miocene fusion events. Ancestral area analysis showed that the genus Xylocopa most likely had an Oriental‐Palaearctic origin and that the present world distribution of Xylocopa subgenera resulted mainly from independent dispersal events. The influence of Pleistocene glaciations on carpenter bee distributions is also discussed. © 2002 The Linnean Society of London, Biological Journal of the Linnean Society, 2002, 77 , 249–266.     

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 phylogenetics and the historical biogeography of dippers (Cinclus)

I used combined sequences of mitochondrial cytochrome  b and ND2 genes to determine the molecular phylogenetic relationships of all five extant species of dipper ( Cinclus ), as well as the relationships of Cinclidae to postulated nearest relatives. All methods of analysis resulted in a single best tree of dipper relationships, uniting the two South American taxa (as sisters) with the single North American exemplar, and the two Eurasian taxa forming a sister clade to the New World taxa. Further, each tree identified thrushes (Turdidae) as the closest relative to Cinclidae. Based on relationships within Cinclus , a Eurasian ancestral area is proposed, with subsequent movement into the New World. Dating of species divergences suggest that dippers arose approximately 4 mya, and achieved their present continental distributions soon after.     

New species of Boswellia and Commiphora (Burseraceae) from Somalia

The new species Boswellia globosa, from the foothills of the limestone escarpment along the Gulf of Aden in northern Somalia, and Commiphora lacerata, from a rocky limestone slope near the coast of the Indian Ocean in north‐eastern Somalia, are described and illustrated.     

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.     

The phylogenetic history and biogeography of the frankincense and myrrh family (Burseraceae) based on nuclear and chloroplast sequence data

Generalized hypotheses for the vicariant, Gondwanan origin of pantropically distributed eudicotyledon families must be refined to accommodate recently revised dates that indicate major continental rifting events predate the evolution of many tricolpate angiosperm clades. Here, we use molecular phylogenies of an eudicotyledon family previously hypothesized to have a Gondwanan origin, the Burseraceae, to test this and other alternative biogeographical hypotheses in light of recalibrated geological events. Phylogenies based on nuclear and chloroplast data were reconstructed for 13 of the 18 genera (50 spp. total) of Burseraceae using parsimony, maximum likelihood, and Bayesian methods. Ages of all lineages were estimated using penalized likelihood and semiparametric rate smoothing [Bioinformatics 2003 (19) 301], which allows the user to calibrate phylogenies based on non-clock-like DNA sequence data with fossil information. Biogeographical hypotheses were tested by comparing ages of species and more inclusive lineages with their extant and most parsimonious ancestral distributions. Our data support a North American Paleocene origin for the Burseraceae followed by dispersal of ancestral lineages to eastern Laurasia and Southern Hemisphere continents.     

Molecular phylogenetics and historical biogeography of Hawaiian Dryopteris (Dryopteridaceae)

The fern genus Dryopteris (Dryopteridaceae) is represented in the Hawaiian Islands by 18 endemic taxa and one non-endemic, native species. The goals of this study were to determine whether Dryopteris in Hawai'i is monophyletic and to infer the biogeographical origins of Hawaiian Dryopteris by determining the geographical distributions of their closest living relatives. We sequenced two chloroplast DNA fragments, rbcL and the trnL-F intergenic spacer (IGS), for 18 Hawaiian taxa, 45 non-Hawaiian taxa, and two outgroup species. For individual fragments, we estimated phylogenetic relationships using Bayesian inference and maximum parsimony. We performed a combined analysis of both cpDNA fragments employing Bayesian inference, maximum parsimony, and maximum likelihood. These analyses indicate that Hawaiian Dryopteris is not monophyletic, and that there were at least five separate colonizations of the Hawaiian Islands by different species of dryopteroid ferns, with most of the five groups having closest relatives in SE Asia. The results suggest that one colonizing ancestor, perhaps from SE Asia, gave rise to eight endemic taxa (the glabra group). Another colonizing ancestor, also possibly from SE Asia, gave rise to a group of five endemic taxa (the exindusiate group). Dryopteris fusco-atra and its two varieties, which are endemic to Hawai'i, most likely diversified from a SE Asian ancestor. The Hawaiian endemic Nothoperanema rubiginosum has its closest relatives in SE Asia, and while the remaining two species, D. wallichiana and D. subbipinnata, are sister species, their biogeographical origins could not be determined from these analyses due to the widespread distributions of D. wallichiana and its closest non-Hawaiian relative.     

Molecular systematics and biogeography of the amphibious genus Littorella (Plantaginaceae)

Littorella (Plantaginaceae) is a disjunct, amphibious genus represented by three closely related species. Littorella uniflora occurs in Europe including Iceland and the Azores, L. americana is found in temperate North America, and L. australis grows in temperate South America. Littorella has been recognized in numerous floristic treatments, but its status as a genus has recently been questioned. Rahn (Botanical Journal of the Linnean Society 120: 145-198, 1996) proposed a new phylogeny for Plantaginaceae based on morphological, embryological, and chemical data in which he reduced Littorella to a subgenus of Plantago. This article compares the phylogeny proposed by Rahn to one based on DNA sequence data from the internal transcribed spacer (ITS) region. In our analysis, Littorella forms a strongly supported monophyletic clade sister to Plantago and its recognition at the generic rank appears warranted. Littorella australis is sister to L. americana, and this clade is sister to the European L. uniflora. This more distant relationship between L. uniflora and L. americana provides support for maintaining both taxa at the specific rank and suggests a European origin for Littorella. Our studies also indicate that the monotypic genus Bougueria is deeply nested within Plantago and that its inclusion within Plantago as proposed by Rahn appears justified.     

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.     

Molecular phylogeny and historical biogeography of the Holarctic wetland leaf beetle of the genus Plateumaris

Leaf beetles of the genus Plateumaris inhabit wetlands across the temperate zone of the Holarctic region. To explore the phylogeographic relationships among North American, East Asian, and European members of this genus and the origin of the species endemic to Japan, we studied the molecular phylogeny of 20 of the 27 species in this genus using partial sequences of mitochondrial cytochrome oxidase subunit I (COI) and the 16S and nuclear 28S rRNA genes. The molecular phylogeny revealed that three species endemic to Europe are monophyletic and sister to the remaining 11 North American and six Asian species. Within the latter clade, North American and Asian species did not show reciprocal monophyly. Dispersal-vicariance analysis and divergence time estimation revealed that the European and North America-Asian lineages diverged during the Eocene. Moreover, subsequent differentiation occurred repeatedly between North American and Asian species, which was facilitated by three dispersal events from North America to Asia and one in the opposite direction during the late Eocene through the late Miocene. Two Japanese endemics originated from different divergence events; one differentiated from the mainland lineage after differentiation from the North American lineage, whereas the other showed a deep coalescence from the North American lineage with no present-day sister species on the East Asian mainland. This study of extant insects provides molecular phylogenetic evidence for ancient vicariance between Europe and East Asia-North America, and for more recent (but pre-Pleistocene) faunal exchanges between East Asia and North America.     

Data reassessment in a phylogenetic context gives insight into chromosome evolution in the giant genus Solanum (Solanaceae)

Chromosome data are fundamental in evolution. However, there has been no attempt to synthesize and evaluate the significance of such information from a phylogenetic perspective in the giant genus Solanum, which was the aim of this work. New and published information of the main cytotaxonomic features (chromosome number, polyploidy, total length of the haploid complement, mean chromosome length, mean arm ratio, karyotype formula, nuclear DNA amount, number/position of rDNA sites) was compiled and mapped onto an embracing Solanaceae phylogeny, performing Ancestral States Reconstruction. There were 506 Solanum species with chromosome counts (49.7% from an estimated total of 1,018 spp.), with x?=?12 being the most frequent number (97%). Species with karyotypes represent 18.8%, while 8% have been studied with any molecular cytogenetic technique. Chromosome characters showed transitions associated with supported nodes, some of which have undergone fewer transitions than others. The common ancestor of all Solanum was a diploid with 2n?=?24, a karyotype with st and/or t chromosomes, 2C DNA content of 1–1.2 pg, one locus of 18–5.8–26S rDNA and one of 5S, both loci being asyntenic. The chromosomal variables behave as homoplastic, with reversions in all branches. The analysed characters were sorted from more to less conserved: asynteny of rDNA loci; number of sites of 18–5.8–26S; chromosome number; karyotype formula; number of 5S loci. This pattern of chromosomal evolution distinguishes Solanum from closely related genera and from genera from other families with a similar number of species.     

Molecular phylogenetic analysis of the genus Strongyloides and related nematodes

Strongyloides spp., parasitic nematodes of humans and many other terrestrial vertebrates, display an unusual heterogonic lifecycle involving alternating parasitic and free-living adult reproductive stages. A number of other genera have similar lifecycles, but their relationships to Strongyloides have not been clarified. We have inferred a phylogeny of 12 species of Strongyloides, Parastrongyloides, Rhabdias and Rhabditophanes using small subunit ribosomal RNA gene (SSU rDNA) sequences. The lineage leading to Strongyloides appears to have arisen within parasites of terrestrial invertebrates. Inferred lifecycle evolution was particularly dynamic within these nematodes. Importantly, the free-living Rhabditophanes sp. KR3021 is placed within a clade of parasitic taxa, suggesting that this species may represent a reversion to a non-parasitic lifecycle. Species within the genus Strongyloides are very closely related, despite the disparity of host species parasitised. The highly pathogenic human parasite Strongyloides fuelleborni kelleyi is not supported as a subspecies of the primate parasite S. fuelleborni fuelleborni, but is most likely derived from a local zoonotic source.     

Molecular phylogeny,biogeography and chromosome evolution of Malagasy dwarf geckos of the genus Lygodactylus (Squamata,Gekkonidae)

We performed a phylogenetic analysis using nuclear (RAG‐1, RAG‐2) and mitochondrial (16S) markers, a statistical Bayesian reconstruction of ancestral distribution areas and a karyological analysis on most Malagasy species of the gekkonid genus Lygodactylus. The phylogenetic analysis largely confirms major basal branching pattern of previous molecular studies, but highlights significant differences concerning both the relationships between different species groups as well as those within groups. The biogeographic analysis supports a Malagasy origin of Lygodactylus, an oversea dispersal to continental Africa and a return to Madagascar. The L. madagascariensis group (also including a new candidate species identified herein) is the most basal clade in Lygodactylus, and the sister group of a clade with all the remaining species. The second most basal clade is the L. verticillatus group, placed as the sister group of a clade comprising African and Malagasy species. The sister lineage of the L. verticillatus group originated the African radiation through an oversea dispersal out of Madagascar. Eventually, the sister lineage of the L. capensis group originated secondary dispersals from Africa to Madagascar. In Madagascar, lineage diversification in different species groups mainly occurred from southern to northern and eastern regions. Dispersal, vicariance and paleoclimatic refugia probably played a relevant role in the evolutionary history of closely related taxa and in speciation mechanisms. The cytogenetic analysis evidenced a high karyotypic variability in Lygodactylus (from 2n = 34 to 2n = 40), which is at least partly consistent with the phylogenetic relationships and the composition of the various species group. Chromosome evolution occurred independently in different lineages, mainly through a reduction in the chromosome number and starting from a putative primitive karyotype of 2n = 40 with all telocentric elements.