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Dive into the research topics where Loren K. Ammerman is active.

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Featured researches published by Loren K. Ammerman.


Herpetological Monographs | 1993

RIBOSOMAL DNA AND THE PHYLOGENY OF FROGS

David M. Hillis; Loren K. Ammerman; Michael T. Dixon; Rafael O. de Sá

Phylogenetic analysis of 1656 aligned sites in the 28S ribosomal RNA gene of frogs supports some of the recently recognized higher groups of anurans but provides counter-support for others. The 28S rDNA data support the monophyly of the recently recognized Pipanura (me- sobatrachians plus neobatrachians), which in turn indicates paraphyly of archaeobatrachians. Me- sobatrachians (pelobatoids plus pipoids), which are either considered paraphyletic or weakly sup- ported as monophyletic in morphological analyses, also receive support as a monophyletic group from the 28S rDNA data. Hyloidea (= Bufonoidea), which is widely recognized but lacks mor- phological support, receives some molecular support as being monophyletic. However, Ranoidea, which is supported by morphology, is counter-supported by ribosomal DNA. In particular, den- drobatids do not group with ranids (but sometimes group with hyloids). A combined analysis of the molecular data with the morphological data of Duellman and Trueb (1986:Biology of Am- phibians) supports Pipanura, Mesobatrachia, Neobatrachia, and Hyloidea, but shows the ranoids as paraphyletic (with Dendrobatidae related to Hyloidea). The agreement between molecular and morphological data in several regions of the anuran tree indicates an approaching stabilization of traditionally labile higher frog classification.


Herpetological Monographs | 2000

SYSTEMATICS OF PYTHONS OF THE MORELIA AMETHISTINA COMPLEX (SERPENTES: BOIDAE) WITH THE DESCRIPTION OF THREE NEW SPECIES

Michael B. Harvey; David G. Barker; Loren K. Ammerman; Paul T. Chippindale

The scrub pythons (Morelia amethistina complex) are revised based on museum specimens and new material recently collected in eastern Indonesia. Morelia kinghorni (formerly M. amethistina kinghorni) and M. amethistina (formerly M. amethistina amethistina) are recognized as species, and three new species are described. The phylogenetic relationships of scrub pythons are resolved using morphological and molecular characters. Scrub pythons are most closely related to Morelia boeleni and have undergone both ancient divergences and a relatively recent radiation. The distribution of scrub pythons corresponds well with areas of endemism recognized in earlier studies of other taxa. Their distribution and evolution appears to have been shaped by combined effects of dispersal and vicariance. Scrub python populations exhibit interesting color and pattern polymorphism and ontogenetic change, and these characteristics vary among populations.


Journal of Mammalogy | 2008

SPECIATION WITHIN BONNETED BATS (GENUS EUMOPS): THE COMPLEXITY OF MORPHOLOGICAL, MITOCHONDRIAL, AND NUCLEAR DATA SETS IN SYSTEMATICS

Molly M. McDonough; Loren K. Ammerman; Robert M. Timm; Hugh H. Genoways; Peter A. Larsen; Robert J. Baker

Abstract We phylogenetically analyze 705 base pairs of the cytochrome-b gene and 351 amplified fragment length polymorphism (AFLP) bands from populations of the karyotypically variable Wagners bonneted bat, Eumops glaucinus, and the Florida bonneted bat, Eumops floridanus (Chiroptera: Molossidae). Three karyotypes have been documented across the range of E. glaucinus, and we report that the karyotype from Cuba is morphologically similar to that from Jamaica. A 4th karyotype is present in specimens from western Ecuador. Three distinct lineages are present in both the cytochrome-b and AFLP trees. One lineage is restricted to western Ecuador and exhibits cytochrome-b divergence values comparable to the values seen between recognized species of Eumops, suggesting that this lineage represents a distinct species. The other 2 lineages are distributed in disjunct areas: Paraguay and Venezuela; and Mexico, the Caribbean, and the United States. Specimens of E. floridanus are morphologically distinct from E. glaucinus, but cannot be distinguished by examination of cytochrome-b or AFLP DNA data. We conclude that there are 4 species in the E. glaucinus complex—E. glaucinus (South America east of the Andes), E. ferox (Caribbean, Mexico, and Central America), E. floridanus in south Florida, and an unnamed taxon in western Ecuador. Speciation is a complex process and no single mechanism, model, concept, or definition is likely to cover all the diverse patterns observed.


Journal of Mammalogy | 2012

First molecular phylogenetic insights into the evolution of free-tailed bats in the subfamily Molossinae (Molossidae, Chiroptera)

Loren K. Ammerman; Dana N. Lee; T. Marie Tipps

Abstract Previous understanding of the relationships among genera of bats in the family Molossidae was based largely on phenetic analyses of morphological data. Relationships among the genera of this family have not been tested with molecular data and, thus, the objective of this study was to construct a phylogeny of representative members of free-tailed bats using DNA sequence data from 1 mitochondrial locus (Nicotinamide adenine dinucleotide dehydrogenase subunit 1 [ND1]) and 3 nuclear loci (dentin matrix protein 1 exon 6 [DMP1], beta fibrinogen intron 7 [&bgr;FIB], and recombination activating gene 2 [RAG2]) for members of the subfamily Molossinae and outgroups from the families Vespertilionidae and Natalidae. Data for each gene were analyzed separately using maximum-likelihood and Bayesian methods and also analyzed in a single combined analysis of a total of 3,216 base pairs. Divergence times were estimated from the combined data set using BEAST analysis. Few intergeneric relationships were significantly supported by mitochondrial data; however, monophyly of most genera was supported. Nuclear results supported a Chaerephon–Mops clade; a New World clade consisting of Eumops, Molossus, Promops, Molossops (including Neoplatymops), Cynomops, and Nyctinomops; and a basal divergence for Cheiromeles. Divergence analysis suggested a Paleocene origin for the family and a split between molossids in the Old World and New World around 29 million years ago. Generally, relationships recovered in our analyses reflected biogeographic proximity of species and did not support the hypotheses of relationship proposed by morphological data.


Journal of Mammalogy | 2004

MITOCHONDRIAL DNA DIVERGENCE DOES NOT REFLECT MORPHOLOGICAL DIFFERENCE BETWEEN MYOTIS CALIFORNICUS AND MYOTIS CILIOLABRUM

Rogelio M. Rodriguez; Loren K. Ammerman

Abstract The California myotis, Myotis californicus, and western small-footed myotis, Myotis ciliolabrum, are 2 morphologically similar bats which have had a complex taxonomic history due to intraspecific geographic variation across their sympatric distribution in western North America. Despite several published differences, field identification remains problematic in the southwestern United States. Mitochondrial cytochrome-b and control region fragments were amplified from tissue samples (n = 20) from Texas, Oklahoma, New Mexico, Arizona, Utah, and California to examine species boundaries and phylogenetic relationships. DNA sequences (1,184 bp) were used in parsimony and maximum-likelihood analyses. To corroborate species identification, cranial measurements from all specimens included in the molecular analysis along with additional specimens were analyzed statistically using principal components analysis (PCA). Individuals were designated either as M. californicus or M. ciliolabrum. Molecular analysis placed M. leibii within clades containing both M. californicus and M. ciliolabrum. In addition, sequence divergence and phylogenetic results do not recover distinct lineages for each species (M. californicus and M. ciliolabrum) as recognized by morphology. Our results suggest that these species have recently diverged, or alternatively that they are 1 phenotypically variable species. Based on network estimation of cytochrome-b haplotypes, phylogeographic structure is minimally represented between haplotypes with an east-west separation in the southwestern United States.


Herpetologica | 2003

MOLECULAR SYSTEMATICS OF THE MIDDLE AMERICAN JUMPING PITVIPERS (GENUS ATROPOIDES) AND PHYLOGEOGRAPHY OF THE ATROPOIDES NUMMIFER COMPLEX

Todd A. Castoe; Paul T. Chippindale; Jonathan A. Campbell; Loren K. Ammerman; Christopher L. Parkinson

We used 1400 bp of mitochondrial DNA sequence from two gene fragments (ND4 and cyt-b) to investigate phylogenetic relationships within Atropoides, with emphasis on the subspecies of A. nummifer. Although many relationships within the genus are strongly supported, monophyly of Atropoides was never supported, although it could not be rejected with statistical confidence. In most analyses, the genus was paraphyletic with respect to Porthidium and Cerrophidion, due to the problematic placement of A. picadoi. Our results suggest that the current taxonomy may underestimate species diversity within this group. Atropoides nummifer was found to comprise three distinct phylogroups, generally coinciding with the current subspecies recognized under A. nummifer but paraphyletic with respect to A. olmec. Additionally, disjunct populations previously thought to represent A. nummifer in Oaxaca, Mexico, and Baja Verapaz, Guatemala, appear to represent A. olmec. We use the phylogeny recovered for A. nummifer and A. olmec to discuss geological and climatic events that may historically have affected gene flow within this complex.


Acta Chiropterologica | 2009

New Species of Bonneted Bat, Genus Eumops (Chiroptera: Molossidae) from the Lowlands of Western Ecuador and Peru

Robert J. Baker; Molly M. McDonough; Vicki J. Swier; Peter A. Larsen; Juan P. Carrera; Loren K. Ammerman

We describe and formally name a species of bonneted bat (genus Eumops), which is a member of the E. glaucinus complex. Closely related species are E. glaucinus, E. ferox, and E. floridanus. The conceptual basis for the description of this species is the Genetic Species Concept with speciation by the Bateson-Dobzhanzky-Muller model. The new species is distinguished from all other species of bats by its unique karyotype (2N = 38, FN = 54), sequence of the mitochondrial cytochrome-b gene, and genetic markers revealed through analysis of Amplified Fragment Length Polymorphisms. The series from the type locality (Ecuador, Guayas) is comprised of seven specimens. Morphologically, the new species is smaller than E. floridanus and E. glaucinus, but is indistinguishable from E. ferox. The new species is significantly smaller in size than E. glaucinus in six out of eight measurements and is distinguishable from E. glaucinus based on length of maxillary toothrow and zygomatic breadth. The geographic range of E. wilsoni, as currently documented, is the dry forests of southwestern Ecuador and adjacent northwestern Peru. We propose the common name for this species be Wilsons bonneted bat.


Journal of Medical Entomology | 2001

Bat Ectoparasites from the Trans-Pecos Region of Texas, Including Notes from Big Bend National Park

C. M. Ritzi; Loren K. Ammerman; Michael T. Dixon; J. V. Richerson

Abstract Ectoparasites of 13 species of molossid, mormoopid, and vespertilionid bats from the Trans-Pecos region of Texas were studied, as follows: Antrozous pallidus (LeConte), Corynorhinus townsendii (Cooper), Eptesicus fuscus (Palisot de Beauvois), Lasiurus cinereus (Palisot de Beauvois), Mormoops megalophylla (Peters), Myotis thysanodes G. S. Miller, Myotis velifer (J. A. Allen), Myotis volans(H. Allen), Myotis yumanensis (H. Allen), Nyctinomops femorosaccus (Merriam), Nyctinomops macrotis (Gray), Pipistrellus hesperus (H. Allen), and Tadarida brasiliensis (I. Geof. St.-Hilaire). The bats were netted, examined for ectoparasites and released. Ectoparasites recovered included three species of flea, three species of streblid, three species of nycteribiid, two species of cimicid, two species of tick, and 17 species of mite. New ectoparasite records are given for hosts in seven instances and for the Trans-Pecos region of Texas in three instances.


Environmental Biology of Fishes | 1991

The relationships of the coelacanth Latimeria chalumnae: evidence from sequences of vertebrate 28S ribosomal RNA genes

David M. Hillis; Michael T. Dixon; Loren K. Ammerman

A subgenomic library created from genomic DNA of Latimeria chalumnae was screened for 28S ribosomal RNA (rRNA) clones. The resulting clone was subcloned into a plasmid vector, and over 2 kb of the 28S rRNA region was sequenced. Sequences of 28S rRNA genes were also obtained for Rhineura floridana (Squamata), Cyprinella lutrensis (Actinopterygii), and Lampetra aepyptera (Petromyzontiformes) by cloning and/or amplification by the polymerase chain reaction. The 28S rDNA sequences were aligned for all the above species as well as for the previously published 28S rDNA sequences of the genera Mus, Rattus, and Homo (Mammalia), Xenopus (Amphibia), and Drosophila (Insecta). Phylogenetic analysis of these species (using both the insect and lamprey sequences for outgroup comparison, or using only the lamprey sequence in the outgroup) produced a single optimal solution: (Outgroup(Cyprinella(Latimeria(Xenopus(Rhineura(Homo(Rattus(Mus)))))))). Bootstrap analysis indicated that the placement of L. chalumnae on this tree was significant at p < 0.01. Previously published alternative hypotheses of relationships of Latimeria require at least 19 additional steps compared to the optimal solution; the rDNA data are sufficient to reject the hypotheses that place Latimeria in groups other than the sarcopterygians.


Journal of Mammalogy | 2013

Molecular systematics of bonneted bats (Molossidae: Eumops) based on mitochondrial and nuclear DNA sequences

Sarah N. Bartlett; Molly M. McDonough; Loren K. Ammerman

Abstract Previous understanding of the relationships among the species of bats in the genus Eumops has been primarily based on phenetic and cladistic analyses of morphological genetic similarity data. The objective of this study was to construct a phylogeny using DNA sequence data from 2 mitochondrial loci (cytochrome-b [Cytb] and nicotinamide adenine dinucleotide dehydrogenase subunit 1 [ND1]) and 1 nuclear locus (β-fibrinogen intron 7 [βFib]) for members of Eumops and outgroups from the family Molossidae. Data for each locus were analyzed separately using maximum-likelihood and Bayesian methods and combined for complete data analyses using Bayesian inference and Bayesian concordance analysis on a total of 2,715 base pairs. The monophyly of Eumops was significantly supported in all analyses and molecular dating estimated a most recent common ancestor of the genus at approximately 15.7 million years ago. Placement of E. hansae was problematic, with ND1 analyses supporting a sister relationship with E. patagonicus and E. nanus, whereas Cytb and βFib analyses placed this species as a basal lineage in the genus. Analysis of all genes recovered E. hansae as a poorly supported basal lineage with E. patagonicus and E. nanus as sister to the remaining species. These 3 major lineages of Eumops diverged during the mid-Miocene.

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Michael T. Dixon

University of Texas at Austin

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David M. Hillis

University of Texas at Austin

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Jonathan A. Campbell

University of Texas at Arlington

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Paul T. Chippindale

University of Texas at Arlington

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