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PubMed2005

Trichoderma biodiversity in China: evidence for a North to South distribution of species in East Asia.

Towards assessing the biodiversity and biogeography of Trichoderma, we have analyzed the occurrence of Trichoderma species in soil and litter from four areas in China: North (Hebei province), South-East (Zhejiang province), West (Himalayan, Tibet) and South-West (Yunnan province). One hundred and thirty five isolates were grouped according to tentative morphological identification. A representative 64 isolates were verified at the species level by the oligonucleotide barcode program TrichO Key v.1.0 and the custom BLAST server TrichoBLAST, using sequences of the ITS1 and 2 region of the rRNA cluster and from the longest intron of the tef1 (translation elongation factor 1-alpha) gene. Eleven known species (Trichoderma asperellum, T. koningii, T. atroviride, T. viride, T. velutinum, T. cerinum, T. virens, T. harzianum, T. sinensis, T. citrinoviride, T. longibrachiatum) and two putative new species (T. sp. C1, and T. sp. C2), distinguished from known species both by morphological characters and phylogenetic analysis, were identified. A significant difference in the occurrence of these species was found between the North (Hebei) and South-West (Yunnan) areas, which correlates with previously reported species distributions in Siberia and South-East Asia, respectively. As in previous studies, T. harzianum accounted for almost half of the biodiversity; although, in this study, it was exclusively found in the North, and was predominantly represented by an ITS1 and 2 haplotype, which has so far been rarely found elsewhere. This study therefore reveals a North-South gradient in species distribution in East Asia, and identifies Northern China as a potential center of origin of a unique haplotype of T. harzianum.

China↗
PubMed2004

First report of a trichomycete fungus (Zygomycota: Trichomycetes) inhabiting larvae of Simulium ochraceum sensu lato Walker (Diptera: Simuliidae) from the Galapagos Islands.

A collection of the larval black fly Simulium ochraceum sensu lato Walker was made at six lotic habitats on San Cristobal Island, Galapagos Islands, Ecuador, during May 2003. Sixty-eight larvae were assayed for the presence of gut fungi (Zygomycota: Trichomycetes). A trichomycete, designated as Smittium sp. was found inhabiting the hindgut of 17.6% of S. ochraceum s.l. larvae. Implications of this finding with respect to both host and trichomycete biogeography are discussed.

Animals↗
PubMed2026

Biogeographic patterns and metabolic potential of chemoautotrophic communities in cold seep sediments across subarctic to tropical regions.

Cold seeps are hotspots of chemoautotrophic primary production, yet how chemoautotrophic community structure and dark carbon fixation (DCF) vary across climatic regions remains unclear. We combined incubation experiments and metagenomics to compare chemoautotrophic communities in cold seep sediments across northwestern Pacific marginal seas, from the subarctic Okhotsk Sea to the tropical South China Sea. Incubation experiments demonstrated higher DCF rates in tropical (1.20 μg C g-1 day-1) than subarctic (0.35 μg C g-1 day-1) sediments (p = 0.002). Analyses of 133 cold seep sediment metagenomes (26 in this study and 107 from NCBI, spanning 0-240 cmbsf) revealed that subarctic chemoautotrophs were dominated by Chloroflexota, Asgardarchaeota, Campylobacterota, and Thermoproteota, whereas tropical chemoautotrophs were dominated by Pseudomonadota and Asgardarchaeota, with higher alpha diversity and integrated co-occurrence networks observed in tropical sediments. Representative genes of the Calvin-Benson-Bassham (CBB) cycle, the 3-hydroxypropionate/4-hydroxybutyrate (3HP/4HB) cycle, and the 3-hydroxypropionate (3HP) bicycle were enriched in tropical sediments, whereas reductive tricarboxylic acid (rTCA) cycle and Wood-Ljungdahl (WL) pathway genes predominated in subarctic sediments. Genome-resolved analysis showed that CBB cycle potential was concentrated in Pseudomonadota in tropical sediments and in Asgardarchaeota in subarctic sediments, and was most strongly correlated with nitrogen metabolism genes, whereas rTCA cycle potential was concentrated in Campylobacterota across both sediments, coupled strongly to sulfur metabolism. Depth profiling revealed surface communities dominated by Campylobacteria using rTCA cycle in subarctic sediments, and Alphaproteobacteria and Gammaproteobacteria using CBB cycle in tropical sediments, whereas the WL pathway predominated in Dehalococcoidia and Lokiarchaeia in the deeper layers of both regions. This study provides a comparative framework for chemoautotrophic biogeography across climatically distinct seeps.

Climate zones↗
PubMed2006

Microsatellite typing reveals strong genetic structure of Schistosoma mansoni from localities in Kenya.

Genetic diversity and population structure of seven populations of Schistosoma mansoni sampled in Kenya were assessed using five microsatellite markers. The mean number of alleles per locus, expected heterozygosity in Hardy-Weinberg equilibrium and pairwise F(ST) values ranged from 5.2 to 10.7, 0.5-0.8 and 3.6-27.3%, respectively. These data reveal that S. mansoni populations in Kenyan have relatively high levels of genetic diversity and is significantly differentiated. Our data combined with information on biogeography support the hypothesis that the strong genetic structure in Kenyan schistosomes is as a result of limited gene flow and large population sizes. Resistance to anthelminthics has not been reported among the Kenyan schistosomes, we hypothesize that this is probably due to the very little gene flow among populations, thereby limiting opportunities for the spread of rare alleles that might confer resistance to the drugs.

Animals↗
PubMed2005

Phylogeny of Taenia: Species definitions and origins of human parasites.

Phylogeny is fundamental as it constrains explanations about history and forms our foundation for recognizing and diagnosing species. In the absence of such a framework taxonomists historically relied on intuitive processes, personal judgment and authority, often embracing a typological view of species that disregarded otherwise unequivocal historical and biological criteria. Species of Taenia are among the most characteristic tapeworms infecting carnivores and humans as definitive hosts and indeed Taeniidae is unique among the Eucestoda in requiring 2 obligate mammalian hosts for transmission; a high percentage (>80%) of life cycles have been completely elucidated among the approximately 45 species and nominal subspecies of Taenia. Until recently there had been no comprehensive attempts at reconstruction of a phylogeny among these important parasites. Such analyses have allowed us to explore the origins and evolution of those independent species of Taenia that occur in humans (T. saginata, T. asiatica, and T. solium) and to understand the ecological and historical processes serving as determinants of biogeography and host-association. These studies supported the status of T. asiatica as a valid species and diagnosed a relationship as the sister-species of T. saginata. These conclusions contrasted with a diversity of opinions that would subsume T. asiatica as a subspecies. Recognition of a species constitutes a specific and testable hypothesis, is not an arbitrary decision and is most appropriately assessed in the context of phylogenetic or historical data. Considering macrospecies, a process has been outlined by Brooks and McLennan [Brooks DR, McLennan DA. The nature of diversity: an evolutionary voyage of discovery. University of Chicago Press: Chicago; 2002] as follows: (1) Discovery: a systematist describes the species; (2) Phylogenetic reconstruction; (3) Evaluation I: do sister-species show geographical overlap-are they sympatric or allopatric (use phylogeny+geographical distributions)? (4) Evaluation II: are sister-species reproductively isolated based on information from natural history, ecology and reproductive biology? Species may be viewed in the context of microevolutionary and macroevolutionary processes. For instance, microspecies are defined in ecological time and involve populations and contemporary process that are potentially reversible (reticulate). In contrast, macrospecies as exemplified by T. saginata and T. asiatica are divergent lineages resulting from processes in evolutionary time where an ancestor has undergone a permanent split that is non-reversible (non-reticulate). Applying these criteria in evaluation of T. saginata and T. asiatica, it becomes clear that in evolutionary time these represent historical lineages with independent spatial and temporal trajectories, having separated from a common ancestor near 0.78 to 1.71 MYBP in Africa, or Eurasia. In ecological time, sympatry, reproductive isolation, and differences in life history evident for T. saginata and T. asiatica as observed in China, and perhaps other regions of Southeast Asia, further serve to validate these taeniids.

Animals↗
PubMed2006

Multiple cosmopolitan ecotypes within a microbial eukaryote morphospecies.

Microbial eukaryotes that are morphologically indistinguishable (i.e. 'morphospecies') tend to be genetically diverse. While most protist morphospecies have cosmopolitan distribution, it has been suggested that ribotypes (unique rRNA gene sequences) or rRNA sequence clusters do have biogeography and such clusters may correlate with particular (non-morphological) adaptations. We have studied this in the ciliated protozoan morphospecies Cyclidium glaucoma. Fifty-four isolates collected worldwide represented 31 distinct ribotypes. There was no evidence of biogeographic distribution patterns. For example, identical ribotypes occurred in samples from Argentina, Peru, Morocco, Russia and Ukraine; in samples from Denmark and Australia; and in samples from Great Salt Lake and hyperhaline ponds in Spain. The morphospecies Cyclidium glaucoma is euryhaline and occurs in freshwater, brackish water, seawater, and hyperhaline waters. Evidence suggests that one ribotype cluster occurs only in marine or brackish habitats, and another one has so far been found only in hyperhaline habitats. Two clades seem to occur only in freshwater, but one clade includes ribotypes that were found in freshwater as well as in brackish water.

Animals↗
PubMed2006

Detection of harmful cyanobacteria and their toxins by both PCR amplification and LC-MS during a bloom event.

We briefly report here the occurrence of toxic blooms in the eutrophic reservoir Billings, São Paulo city, Brazil. Water samples were collected in May 2004, during a cyanobacterial bloom. The presence of toxic species was confirmed by using PCR amplifications of a fragment region of genes encoding microcystin synthetase-mcyB. The determination of toxins was performed by liquid chromatography coupled with mass spectrometry (LC-MS). LC-MS analyses of the toxins from the bloom revealed variants of microcystins (MC), such as MC-LR, MC-RR and MC-YR. HPLC-FLD was used to determine the paralytic shellfish poisoning (PSP) saxitoxin (STX), neosaxitoxin (NEO), gonyautoxins 2 (GTX2) and 3 (GTX3). GTX2, GTX3 and NEO were detected for the first time in a natural sample from Billings reservoir. These results are a contribution to the knowledge of the biogeography of toxic cyanobacteria and their toxins, specifically in São Paulo.

Bacterial Toxins↗
PubMed2005

A dynamic model for the ideal-free distribution as a partial differential equation.

One of the major approaches to understanding spatial effects in ecology and population dynamics is the use of analytic models. Some types of analytic models for spatial effects, such as dispersal models based on partial differential equations or integral kernels, can capture transient behavior and can be easily extended to incorporate population dynamics. Others, such as the ideal-free distribution or the species-area relationship derived from island biogeography theory, only provide equilibrium descriptions of the distribution of organisms or species but do not describe dynamic processes. The goal of this paper is to formulate a class of models based on partial differential equations whose equilibria are solutions to a version of the ideal-free distribution set in continuous space. One motivation is to formulate a dynamic version of the ideal-free distribution which can be compared with or incorporated into other sorts of dynamic models such as reaction-diffusion systems. Another motivation is to show how the global predictions of the ideal-free distribution can arise from simple assumptions about local dispersal behavior. The main results are derivations of partial differential equations using ideas related to Fick's law for diffusion, and alternatively by taking a continuum limit of a discrete model, and a verification that under appropriate hypotheses the solutions to those partial differential equations approach equilibria that satisfy the ideal-free distribution.

Animals↗
PubMed2005

Fire as a global 'herbivore': the ecology and evolution of flammable ecosystems.

It is difficult to find references to fire in general textbooks on ecology, conservation biology or biogeography, in spite of the fact that large parts of the world burn on a regular basis, and that there is a considerable literature on the ecology of fire and its use for managing ecosystems. Fire has been burning ecosystems for hundreds of millions of years, helping to shape global biome distribution and to maintain the structure and function of fire-prone communities. Fire is also a significant evolutionary force, and is one of the first tools that humans used to re-shape their world. Here, we review the recent literature, drawing parallels between fire and herbivores as alternative consumers of vegetation. We point to the common questions, and some surprisingly different answers, that emerge from viewing fire as a globally significant consumer that is analogous to herbivory.

Journal Article↗
PubMed2006

Cryptic species as a window on diversity and conservation.

The taxonomic challenge posed by cryptic species (two or more distinct species classified as a single species) has been recognized for nearly 300 years, but the advent of relatively inexpensive and rapid DNA sequencing has given biologists a new tool for detecting and differentiating morphologically similar species. Here, we synthesize the literature on cryptic and sibling species and discuss trends in their discovery. However, a lack of systematic studies leaves many questions open, such as whether cryptic species are more common in particular habitats, latitudes or taxonomic groups. The discovery of cryptic species is likely to be non-random with regard to taxon and biome and, hence, could have profound implications for evolutionary theory, biogeography and conservation planning.

Adaptation, Biological↗
PubMed2004

Preliminary phylogeny of Valerianaceae (Dipsacales) inferred from nuclear and chloroplast DNA sequence data.

Valerianaceae is a relatively small (ca. 350 species), but morphologically diverse angiosperm clade. Sequence data from the entire ndhF gene, the trnL-F intergenic spacer region, the trnL intron, the matK region, the rbcL-atpB intergenic spacer region and internal transcribed spacer (ITS) region of nuclear ribosomal DNA were collected for 21 taxa within Dipsacaceae and Valerianaceae (1 and 20, respectively). These data were included in several phylogenetic analyses with previously published sequences from Dipsacales. Results from these analyses (maximum parsimony, maximum likelihood, and Bayesian analysis) are in strong agreement with many of the conclusions from previous studies, most importantly: (1) Valerianaceae is sister to Dipsacaceae; (2) Triplostegia is more closely related to species of Dipsacaceae than to Valerianaceae; and (3) Valeriana appears not to be monophyletic, with Valeriana celtica falling outside the remainder of the species of Valeriana sampled here (with very strong support). With the exception of V. celtica, these data support two major clades within Valeriana; one that is exclusively New World and another that is distributed in both the Old and New World. Although the species of Valerianaceae and its sister group Dipsacaceae plus Triplostegia, are widely distributed in the Northern Hemisphere, and the data imply that Valerianaceae diversified initially in Asia (the Himalayan Patrinia and Nardostachys falling at the base of the clade), the center of modern species diversity for the group is in the Andes of South America with as many as 175 species restricted to that region. Although the exclusively South American taxa form a clade in the chloroplast and combined ITS and chloroplast analyses, support values tend to be low. Future studies will need to include additional data, in the form of both characters and taxa, before any strong conclusions about the character evolution, diversification, and biogeography of the South American valerians can be made.

Bayes Theorem↗
PubMed2004

Reconstructing an island radiation using ancient and recent DNA: the extinct and living day geckos (Phelsuma) of the Mascarene islands.

Mitochondrial (12SrRNA and cyt b, 1086 bp) and nuclear (c-mos, 374 bp) DNA sequences were used to investigate relationships and biogeography of 24 living and extinct taxa of Phelsuma geckos. Monophyly of Phelsuma and sister relationship to the SW African Rhoptropella is corroborated. Phelsuma originated on Madagascar and made multiple long-distance invasions of oceanic islands including the Mascarenes, Aldabra, Comores, Seychelles, Andamans, and perhaps Pemba. The Mascarenes were probably colonised once, about 4.2-5.1Ma, and here Phelsuma rosagularis and Phelsuma inexpectata are newly recognised as species, as are three lineages of Phelsuma cepediana. Mascarene relationships are: Phelsuma edwardnewtoni, Phelsuma gigas (Phelsuma guentheri ((((P. cepediana A (P. cepediana B, C)) P. rosagularis) Phelsuma borbonica) ((Phelsuma ornata, P. inexpectata) Phelsuma guimbeaui))). The two recently extinct species, P. edwardnewtoni and the giant secondarily nocturnal Phelsuma gigas, differentiated on Rodrigues while on Mauritius the large nocturnal P. guentheri separated from a small diurnal form that radiated into six species, a likely result of volcanic activity. Two small-bodied lineages from Mauritius invaded the more recent island of Réunion producing two more species. Outside the Mascarenes, two mainly Madagascan assemblages are substantiated: Phelsuma serraticauda (Phelsuma lineata, Phelsuma laticauda, Phelsuma quadriocellata); (Phelsuma m. kochi (Phelsuma m. grandis, Phelsuma abboti)) (Phelsuma astriata, Phelsuma sundbergi). Their relationships to the Mascarene clade, and to Phelsuma mutabilis, Phelsuma standingi and Phelsuma andamanensis are unresolved.

Animals↗
PubMed2004

Molecular systematics of African 20-chromosome toads (Anura: Bufonidae).

Intrageneric lineages and the historical biogeography of toads, genus Bufo, are poorly resolved due to their conservative morphology, their highly conserved karyotypes (typically 2N = 22), and erratic patterns of interspecific hybridisation. Here, we use mitochondrial and nuclear DNA sequence data to reconstruct relationships of the 20-chromosome toads, a major component of the African bufonid fauna. Mitochondrial 12S and 16S sequences from 29 species revealed two independent transitions between phenotypically distinct savannah and forest adapted forms. Analyses of mitochondrial 12S, 16S, and ND2, along with nuclear ACTC and Rhodopsin sequences from 12 species greatly increased bootstrap, and likelihood support for internal branches including a basal split into two pan-African 20-chromosome clades. Hybridisation is a weak indicator of phylogenetic relationship as it occurs across these deeply divergent clades, between Bufo rangeri and Bufo gutturalis. These analyses suggest a secondary reversion to 22-chromosomes in Bufo pardalis, within the 20-chromosome group, although we could not reject an alternative hypothesis that this lineage forms a sister to all 2N = 20 toads. Other informally recognised 22-chromosome groups form independent phylogenetic lineages outside the 20-chromosome group, such as the Angusticeps and Vertebralis divisions. Bufo lindneri, from the Taitanus division, is closely related to Stephopaedes anotis, and these species should be considered congeners.

Africa↗
PubMed2004

Phylogenetic utility of the ribosomal internal transcribed spacer 2 in Strumigenys spp. (Hymenoptera: Formicidae).

Sequence variations and phylogenetic relationships of Strumigenys from different localities in Taiwan were inferred from sequences of the internal transcribed spacer 2 (ITS2) of nuclear ribosomal RNA genes. The ITS2 sequences of different species of Strumigenys vary in length from 659 to 953 bp, because there are many large repeated insertion-deletion fragments, and these short tandem repeat units form microsatellites. The average GC content of the ITS2 is 60.8%. Secondary structures from ITS2 sequences are similar and present several conserved structural motifs. Eleven species and three unnamed species were analyzed using both the maximum parsimony and maximum likelihood methods. Although diversity of the ITS2 sequence is high, these data can still be a potential tool for primary analysis of molecular phylogeny and biogeography of Strumigenys at the species level on islands around Taiwan.

Amino Acid Motifs↗
PubMed2004

Phylogeography of surface and cave Astyanax (Teleostei) from Central and North America based on cytochrome b sequence data.

Astyanax fasciatus has become a model organism for the study of regressive and adaptive evolution in cave animals. To fully understand these processes, it is important to have background information on the systematics and phylogeography of surface and cave populations of this species. Here we investigate the phylogeography of A. fasciatus in North and Central America and also the historical biogeography of this region. Phylogenetic analysis of part of the mtDNA cytochrome b gene from 26 surface and nine cave A. fasciatus populations revealed seven major clades, which, in principle, represent geographical patterns of distribution. However, the four strongly eye and pigment reduced cave populations, Piedras, Sabinos, Tinaja, and Curva, form a separate cluster, which is not sister group to the surface populations from the same locality. Similarly the Belizean populations do not cluster with their geographic neighbors from the Yucatan. The analyses indicate that there have been recurrent invasions of surface Astyanax from the south, that were most likely influenced by major climate changes during the Pleistocene. During this period, ancestors of the strongly eye and pigment reduced cave populations were able to survive underground as thermophilic relics when the surface populations became extinct. The high level of genetic divergence among the different clades shows that differing haplotype lineages must have reinvaded the surface waters from the south and/or back-colonized them from residual habitats and also penetrated into the caves. Nested clade analyses show that recurrent gene flow as well as historic processes like past fragmentation and range expansion have influenced current populations of A. fasciatus in Central and North America. Different haplotype clades of the phylogeny are not compatible with the present taxonomy of Astyanax and, therefore, we propose the application of a single systematic unit, called A. fasciatus.

Animals↗
PubMed2005

Evolutionary history of the synbranchid eels (Teleostei: Synbranchidae) in Central America and the Caribbean islands inferred from their molecular phylogeny.

Swamp eels of the genera Synbranchus and Ophisternon are secondary freshwater fishes whose biogeography provides evidence of their long residence in Mesoamerica, while their impoverished species-level taxonomy might suggest a more recent diversification or a conservative morphology. We have inferred the phylogenetic relationships of Synbranchus marmoratus and Ophisternon aenigmaticum from 45 drainages throughout South, Central America, and Cuba based on mitochondrial genes (cytochrome b and ATPase 8/6). Phylogeographic analysis supported the monophyly of Mesoamerican O. aenigmaticum although our results suggest that S. marmoratus is not a monophyletic group. We found a evolutionary differentiated Synbranchus mtDNA lineage inhabiting Las Perlas islands (Pacific Panama) that appeared to be taxonomically distinct and separated for a long period of time from the main Synbranchus clade. Major synbranchid clades were also corroborated with the nuclear RAG-1 gene (1171-bp). Application of two fish-based mtDNA clocks (1.05-1.3% pairwise divergence/million year (Ma)), is in accordance with the Gondwanian origin suggested for the Synbranchidae. The mtDNA lineages exhibited a remarkable geographic structure in Central America suggesting that vicariance has most likely promoted the Synbranchus and Ophisternon mtDNA diversification. Although our data indicate the importance of the Pacific area in Synbranchus differentiation, the mtDNA divergence between South and Central American Synbranchus is too small to support Cretaceous colonization via the proto-Antillean bridge suggested by Rosen [Syst. Zool. 24 (1976) 431]. Instead, our phylogeographic results suggest that Ophisternon and Synbranchus mtDNA clades most likely colonized Central America during the Miocene (12.7-23Ma) prior the final closure of the Isthmus of Panama (3.3Ma).

Adenosine Triphosphatases↗
PubMed2005

Phylogenetic relationships and evolutionary history of the reef fish family Labridae.

The family Labridae (including scarines and odacines) contains 82 genera and about 600 species of fishes that inhabit coastal and continental shelf waters in tropical and temperate oceans throughout the world. The Labridae (the wrasses) is the fifth largest fish family and second largest marine fish family, and is one of the most morphologically and ecologically diversified families of fishes in size, shape, and color. Labrid phylogeny is a long-standing problem in ichthyology that is part of the larger question of relationships within the suborder Labroidei. A phylogenetic analysis of labrids was conducted to investigate relationships among the six classical tribes of wrasses, the affinities of the wrasses to the parrotfishes (scarines), and the broad phylogenetic structure among labrid genera. Four gene fragments were sequenced from 98 fish species, including 84 labrid fishes and 14 outgroup taxa. Taxa were chosen from all major labrid clades and most major global ocean regions where labrid fishes exist, as well as cichlid, pomacentrid, and embiotocid outgroups. From the mitochondrial genome we sequenced portions of 12S rRNA (1000 bp) and 16S rRNA (585 bp), which were aligned by using a secondary structure model. From the nuclear genome, we sequenced part of the protein-coding genes RAG2 (846 bp) and Tmo4C4 (541 bp). Maximum likelihood, maximum parsimony, and Bayesian analyses on the resulting 2972 bp of DNA sequence produced similar topologies that confirm the monophyly of a family Labridae that includes the parrotfishes and butterfishes and strong support for many previously identified taxonomic subgroups. The tribe Hypsigenyini (hogfishes, tuskfishes) is the sister group to the remaining labrids and includes odacines and the chisel-tooth wrasse Pseudodax moluccanus, a species previously considered close to scarines. Cheilines and scarines are sister-groups, closely related to the temperate Labrini, and pseudocheilines and cheilines are split in all phylogenies. The razorfishes (novaculines) and temperate pseudolabrines form successive sister clades to the large crown group radiation of the Julidini. The cleaner wrasses (Labrichthyini) are nested within this radiation and several julidine genera do not appear to be monophyletic (e.g., Coris and Halichoeres). Invasion of temperate water by this predominantly tropical group has occurred multiple times and the reconstruction of biogeography assuming an Indo-Pacific ancestor results in five different lineages invading the Atlantic/Caribbean region. Functional novelties in the feeding apparatus have allowed labrid fishes to occupy nearly every feeding guild in reef environments, and trophic variation is a central axis of diversification in this family.

Animals↗
PubMed2005

Molecular phylogeny of North American long-eared bats (Vespertilionidae: Corynorhinus); inter- and intraspecific relationships inferred from mitochondrial and nuclear DNA sequences.

The taxonomy of the North American big-eared bats, genus Corynorhinus, was revised by Handley [Handley, C.O., 1959. A revision of the American bats of the genera Euderma and Plecotus. Proc. U.S. Nat. Mus. 110, 95-246] using a morphological systematics approach. Handley employed 17 morphological characters and identified only four characters that reliably differentiated the three species he recognized, C. townsendii, C. rafinesquii, and C. mexicanus. All three species have been shown to lead relatively sedentary lives and have a wing morphology that limits long-distance dispersal. Further, populations of two species, C. townsendii and C. rafinesquii, are considered to be declining. Handley [Handley, C.O., 1959. A revision of the American bats of the genera Euderma and Plecotus. Proc. U.S. Nat. Mus. 110, 95-246] recognized five subspecies of C. townsendii (C. t. australis, C. t. ingens, C. t. pallescens, C. t. townsendii, and C. t. virginianus) and two of C. rafinesquii (C. r. rafinesquii and C. r. macrotis). Two C. townsendii subspecies, C. t. ingens and C. t. virginianus, are listed as endangered under the Endangered Species Act. These facts and the lack of a thorough molecular systematic examination of this genus were the impetus for this study. Using mitochondrial and nuclear intron DNA sequences, a molecular phylogeny was inferred. The combined DNA phylogeny supports Handley's [Handley, C.O., 1959. A revision of the American bats of the genera Euderma and Plecotus. Proc. U. S. Nat. Mus. 110, 95-246] designation of three species. Further the endangered subspecies, C. t. ingens and C. t. virginianus are corroborated, as were the monophyly of the other subspecies. However, the geographical ranges of two of these subspecies, C. t. pallescens and C. t. townsendii, are revised based on biogeographic distributions as understood from our results. Estimates of timing of divergences indicate that the three species, C. townsendii, C. rafinesquii, and C. mexicanus may have diverged before Pleistocene climatic oscillations began, and therefore their cladogenesis was not the result of those processes. However, subspecific divergences within C. townsendii appear to have occurred during and been driven largely by the climatic processes of the Pleistocene Epoch. We propose new hypotheses of dispersal scenarios that may have led to the current biogeography of these lineages.

Animals↗