Biology Commons^™

The Evolution Of Floral Symmetry Across The Plant Order Lamiales, Jinshun Zhong

Dissertations

Bilaterally symmetrical corollas have evolved independently numerous times from radially symmetrical ancestors and are thought to represent adaptation to specific pollinators. However, evolutionary losses of bilateral symmetry have occurred sporadically in different lineages. CYC2-like and RAD-like are genes needed for the normal development of bilateral symmetry in snapdragon corollas. However, exactly how changes in the floral symmetry patterning genes correlate with the origin and loss of floral bilateral remains poorly known. To address this question, a densely sampled phylogeny of CYC2-like genes across the order Lamiales was inferred and calibrated. The expression patterns of these genes in early diverging and …

Phylogeny And Conservation Of The Utah Land Snail Oreohelix Peripherica (Gastropoda: Pulmonata: Camaenidae), Ashley Nelson, Dr. Keith A. Crandall

Journal of Undergraduate Research

This study of the Oreohelix peripherica land snail is a continuation of a study sponsored last year by ORCA. In 1993, Ecosearch, Inc. suggested that O. p. wasatchensis, located at Rainbow Gardens near Ogden, deserved being upgraded to having an endangered status according to the US Endangered Species Act because of its reduced area of occurrence and the depletion of its habitat. The phylogenetic hypothesis gathered from the data obtained in last year’s study suggests that the Rainbow Gardens samples are not endemic to that area because they are genetically similar to other populations from different localities. Since the population …

A Phylogeny Of Robber Flies (Diptera: Asilidae) At The Subfamilial Level: Molecular Evidence, Seth Mikaya Bybee, Dr. Michael Whiting

Journal of Undergraduate Research

Robber flies (Diptera: Asilidae) comprise one of the largest groups of extant flies (Hull, 1962). Asilids constitute more than 500 genera (Woodley, 1989) and more than 5500 species (Lehr, 1988) with a worldwide distribution except Antarctica. Species range in size from less than one centimeter to nearly eight centimeters in length, and their prey consist of both small and large insects caught largely in flight. Asilid color patterns are simple: usually black, gray, or bronze, although some more colorful species appear to mimic bees and wasps. All members of the group, including the problematic group Leptogastrinae (thread-waisted robber flies), form …

A Comparison Of The Phylogeny And Drumming Characteristics In Isogenoides, Christian James Hoybjerg, Dr. Michael F. Whiting

Journal of Undergraduate Research

Isogenoides is a genus of Plecoptera (stoneflies) from the family Perlodidae. The genus is composed of seven separate species and is endemic to North America. Each species has a limited distribution and a distinct system of courtship behavior. The male taps his abdomen on the substrate with a specific “drumming” pattern until he attracts a mate. The female will respond with her own drumming pattern and, in most species, the male confirms the acceptability of the female with a final, distinct answer. This behavior has been hypothesized as both a barrier to cross-species mating and as a mechanism of speciation. …

Phylogeny Of The Freshwater Crayfish Genus Euastacus And Their Coevolution With Ectosymbiotic Temnocephalans, Heather C. Shull, Dr. Keith A. Crandall

Journal of Undergraduate Research

Euastacus crayfish are endemic to the rain forests of the eastern coast of Australia. There are now 43 known species distributed throughout Queensland, New South Wales, and Victoria. Unfortunately many species inhabit areas where human growth, activity, and environmental modification threaten, limit or decrease their population size or natural range (Horwitz 1995; Merrick, 1997). The well being of these crayfish is important because many of these crayfish exist as keystone species in their community. Crayfish are polytrophic and therefore transform energy between a variety of levels and are important for the breakdown of debris (Turvey and Merrick, 1997; Parkyn et …

The Phylogeny Of The Ephemerellidae (Ephemeroptera) Based On Molecular And Morphological Data, Jonathan Osborne, Dr. Michael Whiting

Journal of Undergraduate Research

A prior analysis of the families of Ephemerelloidea, based on 49 morphological characters, supported Ephemerellidae diverging basal to all other Ephemerelloid families (McCafferty and Wang, 2000). The family Ephemerellidae contains twenty genera in two subfamilies (McCafferty and Wang, 2000) and comprises the largest family among the pannote mayflies. Members of this family are distributed throughout Holarctic and Oriental regions.

Phylogeny Of Sap Beetles (Coleoptera: Nitidulidae) Deciphering Patterns Of Host Shift, Matthew Moulton, Dr. Michael F. Whiting

Journal of Undergraduate Research

Nitidulids are a moderately diverse family of beetles, but the evolution of their feeding specializations was poorly understood. They are important in agroecosystems as pests of fruit crops, stored grains, honey production, biocontrol of aphids and scale insects, and transmission of plant viral pathogens. The phylogeny produced helped answer questions pertaining to the evolution of nitidulid host specialization, and provided insights into the diversification of this group. I conducted the first subfamilial phylogenetic analysis based on molecular data. Specific goals were: (1) Perform a phylogenetic analysis using molecular data from eight genes; 2) Use the phylogeny to infer the ancestral …

Phylogeny Of The Tribe Psoraleae In North America, Rebecca Schaeffer, Dr. Keith Crandall

Journal of Undergraduate Research

Many species of plants in the Leguminosae family are important economically, but many of these plants are now considered rare, threatened, or endangered. Seventy percent of the species in the genus Pediomelum are highly limited in geographic distribution, which influences conservation status. In addition to this, very little work with phylogenetic studies has been done on this group. Learning about evolutionary relationships within these species is a first step to understanding more about their conservation status.

Lost Branches On The Tree Of Life, Bryan T. Drew, Romina Gazis, Patricia Cabezas, Kristen S. Swithers, Jiabin Deng, Roseana Rodriguez, Laura A. Katz, Keith A. Crandall, David S. Hibbett, Douglas E. Soltis

Biology

Until recently, uploading sequences to GenBank (or EMBL) was generally considered sufficient to ensure reproducibility of phylogenetic studies using DNA sequence data. Increasingly, however, the systematics community is realizing that archiving raw DNA sequences is not adequate, and that the underlying alignments of DNA sequences as well as the resulting phylogenetic trees are pivotal for reproducibility, comparative purposes, meta-analyses, and ultimately synthesis. Indeed, there has been a growing clamor for journals to adopt and enforce more rigorous data archiving practices across diverse disciplines [4]–[8]. As a result, about 35 evolutionary journals [5],[9] have adopted policies …

Failed Species, Innominate Forms, And The Vain Search For Species Limits: Cryptic Diversity In Dusky Salamanders (Desmognathus) Of Eastern Tennessee, Stephen G. Tilley, Joseph Bernardo, Laura A. Katz, Lizmarie López, J. Devon Roll, Renáe L. Eriksen, Justin Kratovil, Noëlle K.J. Bittner, Keith A. Crandall

Biological Sciences: Faculty Publications

Cytochrome B sequences and allozymes reveal complex patterns of molecular variation in dusky salamander (Desmognathus) populations in eastern Tennessee. One group of allozymically distinctive populations, which we refer to as the Sinking Creek form (SCF), combines morphological attributes of Desmognathus fuscus with cytB sequences characteristic of Desmognathus carolinensis. This form is abruptly replaced by D. fuscus just north of Johnson City, TN with no evidence of either sympatry or gene exchange. To the south, allozymic markers indicate a broad zone of admixture with populations characterized by distinct cytB sequences and that may or may not be ultimately referable to Desmognathus …

Fossil Trachemys (Testudines: Emydidae) From The Late Hemphillian Of Eastern Tennessee And Its Implications For The Evolution Of The Emydidae, Steven E. Jasinski

Electronic Theses and Dissertations

Trachemys (Testudines: Emydidae) represents one of the most well-known turtles today. The evolution of Trachemys, while being heavily documented with various fossil representatives, is not well understood. Numerous fossils from the Gray Fossil Site in northeastern Tennessee are helping to elucidate the taxon’s evolution. The fossil Trachemys at the Gray Fossil Site represent a new species. A review of previously named Trachemys taxa reveals that a huge majority of them are not valid or have been previously misinterpreted. A phylogenetic analysis preformed on modern emydids and supposed fossil representatives of those genera also shows the evolution of a portion …

Systematics Of Longhorned Beetles (Insecta: Coleoptera: Cerambycidae), Eugenio Hernán Nearns

Biology ETDs

The longhorned wood boring beetles (Insecta: Coleoptera: Cerambycidae) are a diverse and economically important group of insects. With an estimated 4,000 genera and more than 35,000 described species, the Cerambycidae comprise one of the largest beetle families. Cerambycid beetles are found on all continents except Antarctica, from sea level to montane sites as high as 4000 m. Cerambycids are among the most serious wood boring pest species globally, affecting many agricultural crops, ornamental trees, and lumber products, causing millions of dollars in damage each year. Despite their economic importance and biological diversity, relatively little is known of cerambycid beetle ecology, …

Diversification And Coexistence In The Madagascar Olive (Noronhia, Oleaceae), Cynthia Hong-Wa

Dissertations

The long-isolated island of Madagascar provides a suitable setting for studying species diversification, with most groups of organisms there both radiating and showing a high level of endemism. Noronhia is one of these groups and represents the most successful radiation of the olive family (Oleaceae) in Madagascar, with ca. 80 species. In this study, using plastid and nuclear DNA sequences obtained from a comprehensive sampling both within Noronhia and the family, I show that Noronhia, together with Indian Ocean species of Chionanthus, form a monophyletic clade sister to African Chionanthus. The diversification of Noronhia followed a likely Cenozoic dispersal from …

Reconstruction Of Family-Level Phylogenetic Relationships Within Demospongiae (Porifera) Using Nuclear Encoded Housekeeping Genes, Malcolm S. Hill, April Hill, Jose Lopez, Kevin J. Peterson

Dartmouth Scholarship

Background: Demosponges are challenging for phylogenetic systematics because of their plastic and relatively simple morphologies and many deep divergences between major clades. To improve understanding of the phylogenetic relationships within Demospongiae, we sequenced and analyzed seven nuclear housekeeping genes involved in a variety of cellular functions from a diverse group of sponges.

Methodology/Principal Findings: We generated data from each of the four sponge classes (i.e., Calcarea, Demospongiae, Hexactinellida, and Homoscleromorpha), but focused on family-level relationships within demosponges. With data for 21 newly sampled families, our Maximum Likelihood and Bayesian-based approaches recovered previously phylogenetically defined taxa: Keratosap, Myxospongiaep, Spongillidap, Haploscleromorphap (the …

Reductive Evolution And The Loss Of Pdc/Pas Domains From The Genus Staphylococcus, Neethu Shah, Rosmarie Gaupp, Hideaki Moriyama, Kent M. Eskridge, Etsuko N. Moriyama, Greg A. Somerville

School of Biological Sciences: Faculty Publications

Background: The Per-Arnt-Sim (PAS) domain represents a ubiquitous structural fold that is involved in bacterial sensing and adaptation systems, including several virulence related functions. Although PAS domains and the subclass of PhoQ-DcuS-CitA (PDC) domains have a common structure, there is limited amino acid sequence similarity. To gain greater insight into the evolution of PDC/PAS domains present in the bacterial kingdom and staphylococci in specific, the PDC/PAS domains from the genomic sequences of 48 bacteria, representing 5 phyla, were identified using the sensitive search method based on HMM-to-HMM comparisons (HHblits).

Results: A total of 1,007 PAS domains and 686 …

Sinularia Leptoclados (Ehrenberg, 1834) (Cnidaria: Octocorallia) Re-Examined, Catherine S. Mcfadden, Leen P. Van Ofwegen, Yehuda Benayahu

All HMC Faculty Publications and Research

Sinularia leptoclados (Ehrenberg, 1834) is re-described. Sinularia leptoclados var. gonatodes Kolonko, 1926 is synonymized with S. maxima Verseveldt, 1977. Two new species of Sinularia with digitiform lobules, leptoclados-type surface clubs and unbranched interior spindles, are described. An updated maximum likelihood tree of Sinularia species with leptoclados-type clubs (clade 5C) based on two mitochondrial genes (mtMutS, COI) and a nuclear gene (28S rDNA) is presented.

Evolutionary Biology For The 21st Century, Jonathan B. Losos, Stevan J. Arnold, Gill Bejerano, E. D. Brodie, David Hibbett, Hopi E. Hoekstra, David P. Mindell, Antónia Monteiro, Craig Moritz, H. Allen Orr, Dmitri A. Petrov, Susanne S. Renner, Robert E. Ricklefs, Pamela S. Soltis, Thomas L. Turner

Biology

Theodosius Dobzhansky famously proclaimed that “nothing makes sense in biology except in the light of evolution." Though Dobzhansky's statement is sometimes dismissed by biologists in other fields as self-promotion, recent advances in many areas of biology have shown it to be prophetic. For example, genomics, which emerged mostly from molecular biology, is now steeped in evolutionary biology. Evolutionary theory helps to explain our origins, our history, and how we function as organisms and interact with other life forms, all of which are crucial to understanding our future (e.g., [1]–[5]). Evolutionary approaches have helped reconstruct the history of …

The Phylogenetics Of Tachinidae (Insecta: Diptera) With An Emphasis On Subfamily Structure, Daniel J. Davis

Browse all Theses and Dissertations

The parasitoid flies of the Tachinidae family are an important and diverse (>10,000 species) lineage of insects. However, tachinids are not well studied partially due to their confusing classification and taxonomy. DNA sequences were obtained from twenty tribal representatives of Tachinidae, along with eight outgroups in order to phylogenetically reconstruct the superfamilial, subfamilial and tribal relationships of Tachinidae. Seven gene regions of six genes (18S, 28S, COI, CAD, Ef1a, and TPI) were sequenced for each taxon (6214 bp total). Both maximum likelihood and Bayesian methods were used to infer phylogenies. The Sarcophagidae and Oestridae were usually reconstructed as monophyletic. …

The Tick Genus Amblyomma In Africa: Phylogeny And Mutilocus Dna Barcoding, Omobolanle Kushimo

College of Graduate Studies: Theses & Dissertations

The tick genus Amblyomma includes approximately 130 species, 28 of which are found on the African continent and/ or in Madagascar. In order to understand the evolutionary phylogeography of the genus, it is necessary to gain a better understanding of the relationships between African taxa. Therefore, the main goals of this work were to, (1) reconstruct the phylogenetic relationships of the African Amblyomma available to us and (2) test markers for their usefulness as barcoding tools to link unknown immature specimens to their corresponding adults. The mitochondrial gene markers used in this study (12SrDNA and COI) did not resolve the …

A Tree Theory Case Study In Steinernema, Camille Eileen Finlinson Porter

Theses and Dissertations

It is widely assumed that current phylogenetic methods are fairly accurate at recovering the evolutionary relationships among different species, but evaluating the relative success of this enterprise is a difficult task. This study addresses some fundamental questions associated with generating phylogenetic trees. The complete genomes of five species of Steinernema were sequenced and assembled. Genes were predicted in AUGUSTUS and orthologous genes were found from those data using OrthoMCL. I aligned 3890 genes in MAFFT and eliminated poorly aligned positions with GBlocks. I created individual trees for each gene as well as a supermatrix tree in PAUP*, using a closely …

Molecular Phylogeny Of Microhylid Frogs (Anura: Microhylidae) With Emphasis On Relationships Among New World Genera, Rafael O. De Sá, Jeffrey W. Streicher, Relebohile Sekonyela, Mauricio C. Forlani, Simon P. Loader, Eli Greenbaum, Stephen Richards, Célio F.B. Haddad

Biology Faculty Publications

Background: Over the last ten years we have seen great efforts focused on revising amphibian systematics. Phylogenetic reconstructions derived from DNA sequence data have played a central role in these revisionary studies but have typically under-sampled the diverse frog family Microhylidae. Here, we present a detailed phylogenetic study focused on expanding previous hypotheses of relationships within this cosmopolitan family. Specifically, we placed an emphasis on assessing relationships among New World genera and those taxa with uncertain phylogenetic affinities (i.e., incertae sedis).

Results: One mitochondrial and three nuclear genes (about 2.8 kb) were sequenced to assess phylogenetic relationships. We utilized an …

Congruence And Indifference Between Two Molecular Markers For Understanding Oral Evolution In The Marynidae Sensu Lato (Ciliophora, Colpodea), Micah Dunthorn, Laura A. Katz, Thorsten Stoeck, Wilhelm Foissner

Biological Sciences: Faculty Publications

Our understanding of the evolution of oral structures within the Colpodida is confounded by the low number of morphological characters that can be used in constructing hypotheses, and by the low taxon and character sampling in molecular phylogenetic analyses designed to assess these hypotheses. Here we increase character sampling by sequencing the mitochondrial SSU-rDNA locus for three isolates of the Marynidae sensu lato. We show that the inferred mitochondrial and nuclear SSU-rDNA trees, as well as concatenated and constrained analyses, are congruent in not recovering a monophyletic Marynidae. However, due to low node support, the trees are indifferent to whether …

Arabidopsis Bhlh100 And Bhlh101 Control Iron Homeostasis Via A Fit-Independent Pathway, Alicia B. Sivitz, Victor Hermand, Catherine Curie, Grégory Vert

Dartmouth Scholarship

Iron deficiency induces a complex set of responses in plants, including developmental and physiological changes, to increase iron uptake from soil. In Arabidopsis, many transporters involved in the absorption and distribution of iron have been identified over the past decade. However, little is known about the signaling pathways and networks driving the various responses to low iron. Only the basic helix–loop–helix (bHLH) transcription factor FIT has been shown to control the expression of the root iron uptake machinery genes FRO2 and IRT1. Here, we characterize the biological role of two other iron-regulated transcription factors, bHLH100 and bHLH101, in iron homeostasis. …

Phylogenetics Of Thysanoptera (Insecta: Paraneoptera), Rebecca S. Buckman

Theses and Dissertations

The order Thysanoptera (Insecta: Paraneoptera), commonly known as thrips, includes organisms that exhibit a wide range of social and feeding behaviors that are of particular interest in evolutionary studies. These studies within thrips have been inhibited by the lack of knowledge of thrips relationships. The recognized classification scheme strives to reflect evolutionary relationships and is based upon morphology. Molecular data is next as morphology alone is not enough to resolve relationships. Few molecular studies have been conducted and all were limited in their taxon sampling and genetic sampling. To provide a foundation of future evolutionary studies, the objectives of this …

Evolution Of Plant Sucrose Uptake Transporters, Anke Reinders, Alicia B. Sivitz, John M. Ward

Dartmouth Scholarship

In angiosperms, sucrose uptake transporters (SUTs) have important functions especially in vascular tissue. Here we explore the evolutionary origins of SUTs by analysis of angiosperm SUTs and homologous transporters in a vascular early land plant, Selaginella moellendorffii, and a non-vascular plant, the bryophyte Physcomitrella patens, the charophyte algae Chlorokybus atmosphyticus, several red algae and fission yeast, Schizosaccharomyces pombe. Plant SUTs cluster into three types by phylogenetic analysis. Previous studies using angiosperms had shown that types I and II are localized to the plasma membrane while type III SUTs are associated with vacuolar membrane. SUT homologs were …

Phylogenetic Search Through Partial Tree Mixing., Kenneth Sundberg, Mark Clement, Quinn Snell, Dan Ventura, Michael Whiting, Keith Crandall

Computational Biology Institute

BACKGROUND: Recent advances in sequencing technology have created large data sets upon which phylogenetic inference can be performed. Current research is limited by the prohibitive time necessary to perform tree search on a reasonable number of individuals. This research develops new phylogenetic algorithms that can operate on tens of thousands of species in a reasonable amount of time through several innovative search techniques.

RESULTS: When compared to popular phylogenetic search algorithms, better trees are found much more quickly for large data sets. These algorithms are incorporated in the PSODA application available at http://dna.cs.byu.edu/psoda

CONCLUSIONS: The use of Partial Tree Mixing …

Testing Phylogenetic Hypotheses Of The Subgenera Of The Freshwater Crayfish Genus Cambarus (Decapoda: Cambaridae)., Jesse W Breinholt, Megan L Porter, Keith A Crandall

Computational Biology Institute

BACKGROUND: The genus Cambarus is one of three most species rich crayfish genera in the Northern Hemisphere. The genus has its center of diversity in the Southern Appalachians of the United States and has been divided into 12 subgenera. Using Cambarus we test the correspondence of subgeneric designations based on morphology used in traditional crayfish taxonomy to the underlying evolutionary history for these crayfish. We further test for significant correlation and explanatory power of geographic distance, taxonomic model, and a habitat model to estimated phylogenetic distance with multiple variable regression.

METHODOLOGY/PRINCIPAL FINDINGS: We use three mitochondrial and one nuclear gene …

Beyond Building A Tree: Phylogeny Of Pitvipers And Exploration Of Evolutionary Patterns, Allyson Fenwick

Electronic Theses and Dissertations

As generic and higher-scale evolutionary relationships are increasingly well understood, systematists move research in two directions: 1) understanding specieslevel relationships with dense taxon sampling, and 2) evaluating evolutionary patterns using phylogeny. In this study I address both foci of systematic research using pitvipers, subfamily Crotalinae. For direction one, I evaluate the relationships of 96% of pitvipers by combining independent sets of molecular and phenotypic data. I find the inclusion of species with low numbers of informative characters (i.e. less than 100) negatively impacts resolution of the phylogeny, and the addition of independent datasets has no effect on or a small …

Molecular Characterization Of Phylogeneticrelationships In Fritillaria Species Inferred From Chloroplast Trnl-Trnf Sequences, Mi̇ne Türktaş, Meral Aslay, Erdal Kaya, Fahri̇ye Ertuğrul

Turkish Journal of Biology

The genus Fritillaria embraces about 165 taxa in the family Liliaceae. In this study, the molecular phylogenetic relationships between 10 Fritillaria taxa were presented. Fritillaria spp. were collected from their natural habitats, and specimens with different morphological features were obtained via selective breeding. Specimens with the desired characters were presented as promising candidate cultivars for ornamental use. Phylogenetic analysis was based on DNA sequences of the chloroplast trnL-trnF region. The phylogeny was constructed using the neighbor joining, maximum parsimony, maximum likelihood, and Bayesian inference methods. The data showed that the examined Fritillaria spp. were evidently diverged into 2 Fritillaria subgenera. …

A New Genus Of Miniaturized And Pug-Nosed Gecko From South America (Sphaerodactylidae: Gekkota), Tony Gamble, Juan D. Daza, Guarino R. Colli, Laurie J. Vitt, Aaron M. Bauer

Biological Sciences Faculty Research and Publications

Sphaerodactyl geckos comprise five genera distributed across Central and South America and the Caribbean. We estimated phylogenetic relationships among sphaerodactyl genera using both separate and combined analyses of seven nuclear genes. Relationships among genera were incongruent at different loci and phylogenies were characterized by short, in some cases zero-length, internal branches and poor phylogenetic support at most nodes. We recovered a polyphyletic Coleodactylus, with Coleodactylus amazonicus being deeply divergent from the remaining Coleodactylus species sampled. The C. amazonicus lineage possessed unique codon deletions in the genes PTPN₁₂ and RBMX while the remaining Coleodactylus species had unique codon …