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LAUREN M. CHAN, JAMES W. ARCHIE, ANNE D. YODER & LEE A. FITZGERALD (2013) Review of the systematic status of Sceloporus arenicolus Degenhardt and Jones, 1972 with an estimate
No full textChan, Lauren M., Archie, James W., Yoder, Anne D., Fitzgerald, Lee A. (2013): LAUREN M. CHAN, JAMES W. ARCHIE, ANNE D. YODER & LEE A. FITZGERALD (2013) Review of the systematic status of Sceloporus arenicolus Degenhardt and Jones, 1972 with an estimate. Zootaxa 3686 (1): 99-100, DOI: 10.11646/zootaxa.3686.1.
A new species of Emballonura (Chiroptera, Emballonuridae) from the dry regions of Madagascar
No full textGOODMAN, STEVEN M., CARDIFF, SCOTT G., RANIVO, JULIE, RUSSELL, AMY L., YODER, ANNE D. (2006): A New Species of Emballonura (Chiroptera: Emballonuridae) from the Dry Regions of Madagascar. American Museum Novitates 3538 (1): 1-24, DOI: 10.1206/0003-0082(2006)3538[1:ANSOEC]2.0.CO;2, URL: http://www.bioone.org/perlserv/?request=get-abstract&doi=10.1206%2F0003-0082(2006)3538%5B1%3AANSOEC%5D2.0.CO%3B
FIGURE 2. Minimum spanning haplotype networks for all S in Review of the systematic status of Sceloporus arenicolus Degenhardt and Jones, 1972 with an estimate of divergence time
No full textFIGURE 2. Minimum spanning haplotype networks for all S. graciosus group samples sequenced at each of three nuclear loci. Size of each circle corresponds to the frequency of that haplotype. Shading corresponds to clade membership in Figure 3.Published as part of Chan, Lauren M., Archie, James W., Yoder, Anne D. & Fitzgerald, Lee A., 2013, Review of the systematic status of Sceloporus arenicolus Degenhardt and Jones, 1972 with an estimate of divergence time, pp. 312-320 in Zootaxa 3664 (3) on page 316, DOI: 10.11646/zootaxa.3664.3.2, http://zenodo.org/record/526598
Two New Species of Mouse Lemurs (Cheirogaleidae: Microcebus) from Eastern Madagascar
No full textThe number of newly discovered Malagasy vertebrate taxa has multiplied in recent years, emphasizing the importance of complete taxon sampling for phylogenetics, biogeography, functional ecology, and conservation biology, especially in such a biodiversity hotspot. In particular, the diversity of extant lemurs is much higher than previously thought, and we have yet to comprehend fully the full extent of lemuriform biodiversity. A recent genetic analysis of mtDNA and nDNA sequence data in Malagasy mouse lemurs revealed the existence of several novel mtDNA clades based on new field sampling. These geographically defined and previously unrecognized mtDNA clades corresponded precisely to patterns of population structure revealed in the analysis of the nDNA data, thus confirming their evolutionary divergence from other mouse lemur clades. Two of these independently evolving lineages correspond to specimens that were collected by us in the Marolambo and Manantantely/Ivorona regions. Here we summarize the genetic evidence and report on the morphometric and external characteristics of these animals, formally describing them as new species. This report thus brings the number of currently recognized and described mouse lemur species to 20. The forests in which these mouse lemurs were discovered have been heavily degraded in the past decade, prompting the classification of one of the new species as Endangered by the IUCN, even before its formal description. As with several other newly described lemur species, immediate field studies and appropriate conservation actions are therefore urgent
FIGURE 1 in Review of the systematic status of Sceloporus arenicolus Degenhardt and Jones, 1972 with an estimate of divergence time
No full textFIGURE 1. Collection localities for samples from the Sceloporus graciosus group included in this study. Colored symbols correspond to clade membership on Figure 3; three individuals for which we only have sequence data at R35 are indicated with stars. Putative species and subspecies boundaries are shaded for the members of the Sceloporus graciosus group. Sceloporus graciosus graciosus: dark gray distribution, S. g. gracilis: light gray distribution, S. g. vandenburgianus: brown distribution, and S. arenicolus: black distribution.Published as part of Chan, Lauren M., Archie, James W., Yoder, Anne D. & Fitzgerald, Lee A., 2013, Review of the systematic status of Sceloporus arenicolus Degenhardt and Jones, 1972 with an estimate of divergence time, pp. 312-320 in Zootaxa 3664 (3) on page 313, DOI: 10.11646/zootaxa.3664.3.2, http://zenodo.org/record/526598
Cheirogaleid diversity and evolution: big questions about small primates
No full textThe family Cheirogaleidae is arguably the most interesting group of primates alive today. Within this single clade, hypothesized to have originated approximately 25–30 Mya, we find the world's smallest living primate (genus Microcebus), one species that went “missing” for more than three decades (genus Allocebus), the only known obligate hibernator within the primates (genus Cheirogaleus), the only primate species that preys upon other members of its phylogenetic family (genus Mirza), and also, a taxonomic system that has exploded within the past two decades. This taxonomic explosion has been decidedly lopsided, however. Whereas the genus Allocebus has remained monotypic, containing the single species A. trichotis since its original description in 1875 (Günther 1875), the genus Microcebus (mouse lemurs) has gone from a two species system as recently as 1993 to one that that now contains more than 20 recognized species. This apparent skew in species-level diversity cries out for further exploration. Is it an artifact of organismal and geographic sampling bias, with certain species and ecosystems preferentially sampled, or is it based in biology, with some branches of the cheirogaleid tree (namely, the mouse lemurs) intrinsically more prone to evolutionary divergence? An exploration of these themes and questions is our goal in this chapter. The first genus-level phylogeny of the cheirogaleid lemurs was published by Rumpler et al. (1994) and has remained virtually unchanged in the subsequent decades. Using karyotype data and restriction fragment analysis, the authors found strong support for the phylogeny illustrated in Figure 1.1. Notably, Rumpler and Albignac (1972) had long before discovered that the karyotype of Phaner (2n = 46) is quite distinct from that of the other four genera (2n = 66), leading those authors to propose a two-subfamily taxonomy of the Cheirogaleidae, the monotypic Phanerinae (including only the genus Phaner) and the Cheirogaleinae (comprising the four remaining genera). More recent molecular phylogenetic analyses have sampled more densely at the species level and have yielded fresh insights into interspecific relationships within the various genera, while leaving the “skeleton” of the phylogeny unchanged
Concatenation and Concordance in the Reconstruction of Mouse Lemur Phylogeny: An Empirical Demonstration of the Effect of Allele Sampling in Phylogenetics
Full text linkThe systematics and speciation literature is rich with discussion relating to the potential for gene tree/species tree discordance. Numerous mechanisms have been proposed to generate discordance, including differential selection, longbranch attraction, gene duplication, genetic introgression, and/or incomplete lineage sorting. For speciose clades in which divergence has occurred recently and rapidly, recovering the true species tree can be particularly problematic due to incomplete lineage sorting. Unfortunately, the availability of multilocus or “phylogenomic” data sets does not simply solve the problem, particularly when the data are analyzed with standard concatenation techniques. In our study, we conduct a phylogenetic study for a nearly complete species sample of the dwarf and mouse lemur clade, Cheirogaleidae. Mouse lemurs (genus, Microcebus) have been intensively studied over the past decade for reasons relating to their high level of cryptic species diversity, and although there has been emerging consensus regarding the evolutionary diversity contained within the genus, there is no agreement as to the inter-specific relationships within the group. We attempt to resolve cheirogaleid phylogeny, focusing especially on the mouse lemurs, by employing a large multilocus data set. We compare the results of Bayesian concordance methods with those of standard gene concatenation, finding that though concatenation yields the strongest results as measured by statistical support, these results are found to be highly misleading. By employing an approach where individual alleles are treated as operational taxonomic units, we show that phylogenetic results are substantially influenced by the selection of alleles in the concatenation process.
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Species delimitation in lemurs: multiple genetic loci reveal low levels of species diversity in the genus <it>Cheirogaleus</it>
Full text linkAbstract Background Species are viewed as the fundamental unit in most subdisciplines of biology. To conservationists this unit represents the currency for global biodiversity assessments. Even though Madagascar belongs to one of the top eight biodiversity hotspots of the world, the taxonomy of its charismatic lemuriform primates is not stable. Within the last 25 years, the number of described lemur species has more than doubled, with many newly described species identified among the nocturnal and small-bodied cheirogaleids. Here, we characterize the diversity of the dwarf lemurs (genus Cheirogaleus) and assess the status of the seven described species, based on phylogenetic and population genetic analysis of mtDNA (cytb + cox2) and three nuclear markers (adora3, fiba and vWF). Results This study identified three distinct evolutionary lineages within the genus Cheirogaleus. Population genetic cluster analyses revealed a further layer of population divergence with six distinct genotypic clusters. Conclusion Based on the general metapopulation lineage concept and multiple concordant data sets, we identify three exclusive groups of dwarf lemur populations that correspond to three of the seven named species: C. major, C. medius and C. crossleyi. These three species were found to be genealogically exclusive in both mtDNA and nDNA loci and are morphologically distinguishable. The molecular and morphometric data indicate that C. adipicaudatus and C. ravus are synonymous with C. medius and C. major, respectively. Cheirogaleus sibreei falls into the C. medius mtDNA clade, but in morphological analyses the membership is not clearly resolved. We do not have sufficient data to assess the status of C. minusculus. Although additional patterns of population differentiation are evident, there are no clear subdivisions that would warrant additional specific status. We propose that ecological and more geographic data should be collected to confirm these results.</p
Investigating the Intrinsic and Extrinsic Drivers of Primate Heterothermy
No full textSeasonal heterothermy—an orchestrated set of extreme physiological responses—is directly responsible for the over-winter survival of many mammalian groups living in seasonal environments. Historically, it was thought that the use of seasonal heterothermy (i.e. daily torpor and hibernation) was restricted to cold-adapted species; it is now known that such thermoregulatory strategies are used by more species than previously appreciated, including many tropical species. The dwarf and mouse lemurs (family Cheirogaleidae) are among the few primates known to use seasonal heterothermy to avoid Madagascar’s harsh and unpredictable environments. These primates provide an ideal study system for investigating a common mechanism of mammalian seasonal heterothermy. The overarching theme of this dissertation is to understand both the intrinsic and extrinsic drivers of heterothermy in three species of the family Cheirogaleidae. By using transcriptome sequencing to characterize gene expression in both captive and natural settings, we identify unique patterns of differential gene expression that are correlated with extreme changes in physiology in two species of dwarf lemurs: C. medius under captive conditions at the Duke Lemur Center and C. crossleyi studied under field conditions in Madagascar. Genes that are differentially expressed appear to be critical for maintaining the health of these animals when they undergo prolonged periods of metabolic depression concurrent with the hibernation phenotype. Further, a comparative analysis of previously studied mammalian heterotherms identifies shared genetic mechanisms underlying the hibernation phenotype across the phylogeny of mammals. Lastly, conducting a diet manipulation study with a captive colony of mouse lemurs (Microcebus murinus) at the Duke Lemur Center, we investigated the degree to which dietary effects influence torpor patterns. We find that tropical primate heterotherms may be exempt from the traditional paradigms governing cold-adapted heterothermy, having evolved different dietary strategies to tolerate circadian changes in body temperature.</p
Characterization of Vomeronasal Type-1 Receptor (V1R) Repertoire Diversity in Mouse Lemurs (Genus Microcebus)
No full textAn organism's ability to detect and interpret chemical signals from the surrounding environment is vital to its survival. In mammals, the vomeronasal organ provides an integral part of this requirement as it allows for the detection of inter-individual chemical signals. Located within the vomeronasal epithelium is a group of highly specialized receptors called vomeronasal type-1 receptors (V1Rs). These receptors bind pheromones and kairomones, which are chemical cues from conspecifics and heterospecifics, respectively. Recently, V1Rs have been recognized as highly variable across mammalian taxa. One extraordinary example is the mouse lemur, in which ~83% of the estimated 259 genes are expected to be intact. This relatively young and cryptically diverse prosimian group has a controversial history of species delimitation and it is possible that patterns in the rapidly evolving and highly diverse V1R gene family may provide insight into species boundaries. This study generated broad and deep coverage of the two most diverse V1R subfamilies across multiple Microcebus species. By utilizing Pacific Bioscience's single molecule real time sequencing technology, this study produced sequences at a fraction of the time and cost of the traditional method of Sanger-sequenced clones. The results advance our understanding of the high diversity-at least 5.6% and 9.9% sequence divergence intra- and inter-individually for V1RIX and V1Rstrep, respectively-and rapid evolution of V1Rs in mouse lemurs. Comparing these results with draft genome mined sequences demonstrates the limited utility of low coverage genomes for identifying variation in this gene family. The patterns uncovered here provide no clear evidence for the role of these two characterized subfamilies in maintaining or generating species boundaries, but may instead point to an alternative mechanism of species recognition that is more complex and intricate than previously envisioned.</p
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