Evolution Commons^™

Developmental Evolution Of The Visual System In The Cave-Adapted Small Carrion Beetle Ptomaphagus Hirtus, Jasmina Kulacic

Wayne State University Theses

Extensive research has been done to date on Drosophila and Tribolium eye development; however, not much is known about the molecular basis of development of extremely reduced and modified eyes in cave insects. Ptomaphagus hirtus represents an emerging model system for studying the changes at the molecular level that occurred during the evolutionary adaptation of the eye to the cave environment. Therefore, I have started exploring the morphology and organization of the reduced P. hirtus eyelet, using immunohistochemistry, laser scanning microscopy, and ultrastructural imaging approaches. My findings demonstrate that the adult eyelet lacks ommatidial subdivision and has a thick, clear …

Evolution Of New Duplicate Genes In Arabidopsis Thaliana, Nicholas Curtis Marowsky

Wayne State University Theses

Abstract

Gene duplication is one of the major mechanisms by which organisms expand their genomes. The material added to the genome can then be acted upon by mutation and natural selection to increase the fitness of the species. By studying these duplicate sequences we can understand the process by which species evolve new functional genes. In a previous paper we identified 100 new duplicate genes through a genome wide comparison between A. thaliana and related species. We selected three of these new duplicate genes and investigated more closely their sequence and expression divergence from their parental gene. The three new …

Effects Of Proline And Glycine On The Cnidocyte Discharge Of Hydra Magnipapillata, Janine R. Appleton

Honors Theses and Capstones

The sense of taste enables animals to utilize environmental cues to detect favorable foods. Through specialized sensory receptors, Cnidarians employ stinging cells called cnidocytes to perform a variety of activities such as locomotion, capturing prey, inducing of feeding responses, and defense. Their discharge is highly regulated by mechanical and chemical signals that are mediated by a complex system including the opsin and taste pathways. Taste 1 Receptors (T1R) have previously been isolated in vertebrates but only until recently, have been noted in invertebrates. Receptors specific to L- amino acids corresponding to the taste sensation of umami, were studied to determine …

Development Of Neuroendocrine Components Of The Thyroid Axis In The Direct-Developing Frog Eleutherodactylus Coqui: Formation Of The Median Eminence And Onset Of Pituitary Tsh Production., David H. Jennings, Bryce Evans, James Hanken

SIUE Faculty Research, Scholarship, and Creative Activity

Direct-developing frogs lack, wholly or in part, a wide range of larval features found in metamorphosing species and form adult-specific features precociously, during embryogenesis. Most information on thyroid regulation of direct development relies on hormone manipulations; the ontogeny of many thyroid axis components has not been fully described. This analysis examines differentiation of the median eminence of the hypothalamus and production of thyroid-stimulating hormone (TSH) by the pituitary of the direct-developing frog Eleutherodactylus coqui. The median eminence is established two-thirds of the way through embryogenesis. Cells immunoreactive to human TSHb antibodies are first detected during embryogenesis and quantitative changes in …

Target-Directed Biosynthetic Evolution: Redirecting Plant Evolution To Genomically Optimize A Plant’S Pharmacological Profile, Dustin Paul Brown

Theses and Dissertations--Neuroscience

The dissertation describes a novel method for plant drug discovery based on mutation and selection of plant cells. Despite the industry focus on chemical synthesis, plants remain a source of potent and complex bioactive metabolites. Many of these have evolved as defensive compounds targeted on key proteins in the CNS of herbivorous insects, for example the insect dopamine transporter (DAT). Because of homology with the human DAT protein some of these metabolites have high abuse potential, but others may be valuable in treating drug dependence. This dissertation redirects the evolution of a native Lobelia species toward metabolites with greater activity …

The Evolution Of Sex Determination And The Dmrt1 Gene In The Japanese Gecko (Gekko Japonicus), Lisa-Marie Mullen

All Master's Theses

There are different sex-determining mechanisms in our environment, which are separated into two groups known as genotypic sex determination (GSD) and environmental sex determination. The most well-known mechanism in the ESD group is temperature-dependent sex determination (TSD). In this study, the presence of the Doublesex and mab-3-related Transcription Factor (Dmrt1) gene was observed during embryonic development in geckos with a TSD mechanism. To do this, I observed the rate of transcription of the Dmrt1 gene in the Gecko species Gekko japonicus. Pregnant geckos were caught around Nanjing, China. Once the females laid their eggs, the eggs were …

Unraveling The Genetic Mechanisms Involved In The Evolution And Development Of The Thoracic Appendages In Insects, Victor Medved

Wayne State University Dissertations

Insects display the greatest amount of structural and functional variation among animal groups, particularly in regard to their appendage morphology. These differences can range from the diverse pigmentation patterns between fore- and hindwings to changes in the size and shape of legs. The greatly enlarged jumping hind leg in crickets and grasshoppers is one of the best known illustrations of such diversity, representing a unique feature for the entire order of these insects (Orthoptera). Previous work from our lab has shown that the homeotic gene Ultrabithorax (Ubx) plays a key role in the enlargement of hind legs not only in …

Multimodal Signalling In The North American Barn Swallow: A Phenotype Network Approach, Daizaburo Shizuka, Matthew R. Wilkins, Maxwell Joseph, Joanna K. Hubbard, Rebecca Safran

Papers in Behavior in Biological Sciences

Complex signals, involving multiple components within and across modal- ities, are common in animal communication. However, decomposing complex signals into traits and their interactions remains a fundamental challenge for studies of phenotype evolution. We apply a novel phenotype network approach for studying complex signal evolution in the North American barn swallow (Hirundo rustica erythrogaster). We integrate model testing with correlation-based phenotype networks to infer the contributions of female mate choice and male–male competition to the evolution of barn swallow communication. Overall, the best predictors of mate choice were distinct from those for competition, while moderate functional overlap suggests …

Systematics Of The African River Frog Genus Amietia (Anura: Pyxicephalidae) From Eastern Democratic Republic Of The Congo, Thornton Robert Larson

Open Access Theses & Dissertations

The African river frog genus Amietia is found near rivers and other lentic water sources throughout central, eastern and southern Africa. Because the genus includes multiple morphologically conservative species, taxonomic studies of river frogs have been limited. We sampled 49 individuals of Amietia from multiple localities in and near the Albertine Rift (AR) of Burundi, Democratic Republic of the Congo and Uganda. We utilized single-gene (16S) and concatenated (12S, 16S, cytochrome b and RAG1) gene-tree analyses and coalescent species-tree analyses to construct phylogenetic trees. Two divergence dating approaches were used in BEAST, including secondary calibration points with 12S, 16S and …

Phylogeny And Systematics Of Panaspis And Afroablepharus Skinks (Squamata: Scincidae) In The Savannas Of Sub-Saharan Africa, Maria Fernanda Medina

Open Access Theses & Dissertations

African snake-eyed skinks are relatively small lizards of the genera Panaspis and Afroablepharus. The allocation of these genera was frequently rearranged in the 20th century based on morphology, ecology and biogeography. Members of these genera occur primarily in savanna habitats throughout sub-Saharan Africa and include species that have highly conserved morphology, which poses a challenge for taxonomic studies. We sequenced two mitochondrial (16S and cyt b) and two nuclear genes (PDC and RAG1) from 91 Panaspis and Afroablepharus samples from various localities in eastern, central and southern Africa. Concatenated gene-tree and divergence dating analyses were conducted to infer phylogenies and …

Nonstructural Carbohydrate Concentrations Of Pine Trees As A Function Of Evolutionary History, Joshua T. Mims

College of Graduate Studies: Theses & Dissertations

Nonstructural carbohydrates (NSC) can supply substrate during periods when current photosynthate is unavailable or inadequate to meet metabolic demands. I hypothesized that natural selection has favored higher nonstructural carbohydrate concentrations ([NSC]) in species that have an evolutionary history of frequent disturbance and tested this using three southern pine species that have evolved under a continuum of disturbance frequencies (evolutionary history of fire ~ longleaf > slash > loblolly). Stem and root samples were collected from 12 similar-sized individual trees of each species during time periods that reflect the annual minimum and maximum [NSC]. A modified colorimetric method was performed on the samples …

Behavioral Responses Of Male Parasitic Wasps To Plant Cues: A Comparison Of Two Host-Plant Complex Sources Of Cotesia Congregata (Say), Megan Ayers

Theses and Dissertations

Prior exposure to plants cues can enhance assortative mating in insects. We hypothesized that, as previously reported for females, males of Cotesia congregata would display inherent responses to plant cues that could be modified by postemergence experience and further, that males originating from two different host-plant complexes (HPCs) would display different behavioral responses to these HPCs. In no-choice contact assays with a non-host plant, searching responses of males and females increased sharply at Day 2 and remained stable through Day 4. In no-choice assays with potential host plants, males searched longer on catalpa than tobacco; responses were not modified by …

Evolution In Action: Climate Change, Biodiversity Dynamics And Emerging Infectious Disease, Eric P. Hoberg, Daniel R. Brooks

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Climatological variation and ecological perturbation have been pervasive drivers of faunal assembly, structure and diversification for parasites and pathogens through recurrent events of geographical and host colonization at varying spatial and temporal scales of Earth history. Episodic shifts in climate and environmental settings, in conjunction with ecological mechanisms and host switching, are often critical determinants of parasite diversification, a view counter to more than a century of coevolutionary thinking about the nature of complex host–parasite assemblages. Parasites are resource specialists with restricted host ranges, yet shifts onto relatively unrelated hosts are common during phylogenetic diversification of parasite lineages and directly …

Chromosomal Rearrangements Directly Cause Underdominant F1 Pollen Sterility In Mimulus Lewisii-M. Cardinalis Hybrids, Angela M. Stathos

Graduate Student Theses, Dissertations, & Professional Papers

Chromosomal rearrangements can contribute to the evolution of postzygotic reproductive isolation directly, by disrupting meiosis in F₁ hybrids, or indirectly, by suppressing recombination among genic incompatibilities. Because direct effects of rearrangements on fertility imply fitness costs during their spread, understanding the mechanism of F₁ hybrid sterility is integral to reconstructing the role(s) of rearrangements in speciation. In hybrids between monkeyflowers Mimulus cardinalis and M. lewisii, rearrangements contain all quantitative trait loci (QTLs) for both premating barriers and pollen sterility, suggesting that they may have facilitated speciation in this model system. I used artificial chromosome doubling and …

Genetic And Environmental Variation In Condition, Cutaneous Immunity, And Haematocrit In House Wrens, Scott K. Sakaluk, Laura A. Vogel, Alastair J. Wilson, E. Keith Bowers, L. Scott Johnson, Brian S. Masters, Bonnie Gp Johnson, Anna M. Forsman, Charles F. Thompson

Faculty Publications – Biological Sciences

Background

Life-history studies of wild bird populations often focus on the relationship between an individual’s condition and its capacity to mount an immune response, as measured by a commonly-employed assay of cutaneous immunity, the PHA skin test. In addition, haematocrit, the packed cell volume in relation to total blood volume, is often measured as an indicator of physiological performance. A multi-year study of a wild population of house wrens has recently revealed that those exhibiting the highest condition and strongest PHA responses as nestlings are most likely to be recruited to the breeding population and to breed through two years …

Characterization Of The Transcriptome, Nucleotide Sequence Polymorphism, And Natural Selection In The Desert Adapted Mouse Peromyscus Eremicus, Matthew D. Macmanes, Michael B. Eisen

Molecular, Cellular & Biomedical Sciences

As a direct result of intense heat and aridity, deserts are thought to be among the most harsh of environments, particularly for their mammalian inhabitants. Given that osmoregulation can be challenging for these animals, with failure resulting in death, strong selection should be observed on genes related to the maintenance of water and solute balance. One such animal, Peromyscus eremicus, is native to the desert regions of the southwest United States and may live its entire life without oral fluid intake. As a first step toward understanding the genetics that underlie this phenotype, we present a characterization of the …

A Molecular Framework Phylogeny For Ptilotus (Amaranthaceae), Timothy A. Hammer

Biological Sciences Theses & Dissertations

Ptilotus (Amaranthaceae) is an Australian genus with over 100 species, most of which occur in arid Western Australia. Ptilotus has been a taxonomically difficult genus; despite rigorous morphological studies into the genus over many years, previous workers have found it difficult to delimit infrageneric groups due to inconsistent morphological variation. With the goal to establish a phylogenetic framework for the genus, 100 taxa were sampled, including 87 Ptilotus spp., and the ITS nrDNA and matK cpDNA were sequenced. The phylogeny was reconstructed using Bayesian, maximum likelihood and maximum parsimony analyses on separate and concatenated datasets. Morphological characters were assessed and …

Ecological Niches, Species Distributions, And Biogeographic Processes In Rodents On Neotropical Sky Islands, Mariano Soley

Dissertations, Theses, and Capstone Projects

This dissertation focused on the methodological and theoretical improvement of correlative ecological niche models (ENMs) to better understand the processes governing species distributions and associated evolutionary divergence in rodents inhabiting mesic conditions in the Neotropics. Focusing on a widespread rodent from northern South America (Heteromys anomalus), in the first chapter I proposed and tested a methodological approach to surmount the challenge of incorporating environmental information from the margins of species geographic ranges into ENMs. In so doing, I argue how populations that exist on the borders of species' local ranges (spatial margins) can lead to exaggerated estimates of their niches …

Acceptance Of Evolution By America’S Educators Of Prospective Teachers, Guillermo Paz-Y-Miño-C, Avelina Espinosa

New England Science Public: Series Evolution

Paz-y-Miño-C G & Espinosa A. 2014. Acceptance of Evolution by America’s Educators of Prospective Teachers. New England Science Public: Series Evolution 2(1): 1-92 (ISSN: 2326-0971). In NESP Series Evolution Vol 2 No 1, Paz-y-Miño-C and Espinosa use the conceptual framework of the Incompatibility Hypothesis (i.e. science/evolution and belief in supernatural causation are incompatible) to document the patterns of acceptance of evolution of 495 Educators of Prospective Teachers affiliated with 281 colleges and universities widely distributed in 4 regions, 9 divisions, and 50 states in the United States. These higher-education professionals (65% PhD-, 22% doctorate-holders) were polled in five areas: (i) …

A Homogenizing Process Of Selection Has Maintained An 'Ultra-Slow' Acetylation Nat2 Variant In Humans, Blandine Patillon, Pierre Luisi, Estella S. Poloni, Sotiria Boukouvala, Pierre Darlu, E. Genin, Audrey Sabbagh

Human Biology Open Access Pre-Prints

N-acetyltransferase 2 (NAT2) is an important enzyme involved in the metabolism of a wide spectrum of naturally occurring xenobiotics, including therapeutic drugs and common environmental carcinogens. Extensive polymorphism in NAT2 gives rise to a wide interindividual variation in acetylation capacity which influences individual susceptibility to various drug-induced adverse reactions and cancers. Striking patterns of geographic differentiation have been described for the main slow acetylation variants of the NAT2 gene, suggesting the action of natural selection at this locus. In the present study, we took advantage of the whole-genome sequence data available from the 1000 Genomes project to investigate the …