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2023

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Articles 121 - 129 of 129

Full-Text Articles in Evolution

A Cladoxylopsid With Complex Vascular Architecture From The Early Devonian Battery Point Formation (Québec, Canada), Jessica Chu Jan 2023

A Cladoxylopsid With Complex Vascular Architecture From The Early Devonian Battery Point Formation (Québec, Canada), Jessica Chu

Cal Poly Humboldt theses and projects

Cladoxylopsids are seed-free plants that formed the world’s earliest forests and gave rise to horsetails (sphenopsids), but their evolutionary origins are poorly understood. Here, I describe a new Early Devonian cladoxylopsid from the Emsian (400-395 Ma) Battery Point Formation (Québec, Canada). The structural features of this plant indicate taxonomic affinity to cladoxylalean cladoxylopsids and its phylogenetic position supports placement in genus Cladoxylon (the proposed name, Cladoxylon kespekianum sp. nov., to be formalized by peer-reviewed publication). Specimens of this plant are permineralized in calcium carbonate and were studied using the acetate peel technique with light and electron microscopy. Cladoxylon kespekianum is …

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Placing The Evolutionary History Of Desmognathus Salamanders In Context: A Phylogeographic Approach, Kara Jones Jan 2023

Placing The Evolutionary History Of Desmognathus Salamanders In Context: A Phylogeographic Approach, Kara Jones

Theses and Dissertations--Biology

Patterns of genetic variation do not arise in a vacuum but are instead shaped by the interplay between evolutionary forces and ecological constraints. Here, I use a phylogeographic approach to examine the role that ecology played in lineage divergence in the Desmognathus quadramaculatus species complex (Family: Plethodontidae), which consists of three nominal species: D. quadramaculatus, D. marmoratus, and D. folkertsi. Previous phylogenetic studies have shown that individuals from these species do not form clades based on phenotype. My approach to reconciling phylogenetic discordance was two-fold, using (1) genome-wide markers to provide insight into the …

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Attack Of The Clones: Elucidating The Role Of Clonality In The Invasion Success Of Carpobrotus Edulis, Eduardo Luis Cruz Jan 2023

Attack Of The Clones: Elucidating The Role Of Clonality In The Invasion Success Of Carpobrotus Edulis, Eduardo Luis Cruz

Electronic Theses, Projects, and Dissertations

Transcriptomics is a modern technique in genomics that utilizes RNA sequences to get a snapshot of genetic expression. This is a powerful tool in non-model species lacking a reference genome. Thus, the application of comparative transcriptomics has the potential to help us elucidate the evolutionary mechanisms that facilitate species invasion. Carpobrotus edulis is a prolific and widespread invasive succulent plant belonging to the Aizoaceae family. A native to South Africa, this species has become a dominant invader of many Mediterranean coastal areas. In this study, we leveraged the use of RNAseq to investigate evolutionary changes among invasive populations. RNA-seq data …

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Investigation Of The Segment Polarity Network In The Tardigrade Hypsibius Exemplaris, Taylor R. Harrison Jan 2023

Investigation Of The Segment Polarity Network In The Tardigrade Hypsibius Exemplaris, Taylor R. Harrison

UNF Graduate Theses and Dissertations

Segmentation has facilitated the evolution of the many forms of the panarthropods. Downstream regulation of segmentation is controlled by the highly conserved segment polarity network which includes the genes engrailed (en), hedgehog (hh), wingless (wg), cubitus interruptus (ci), patched (ptc), and smoothend (smo). While a high level of conservation has been seen in both the arthropods and onychophorans, only en has been described in any representatives of Tardigrada. Previous work had already established the loss of wg, which encodes for a Wnt ligand, in the tardigrade H. exemplaris …

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The Systems Measurement Of Mammalian Biotas, Part Two, Charles H. Smith, Patrick Georges, Ngoc Nguyen Jan 2023

The Systems Measurement Of Mammalian Biotas, Part Two, Charles H. Smith, Patrick Georges, Ngoc Nguyen

Faculty/Staff Personal Papers

For a recent publication, the authors identified a seven-region model of mammal family distribution patterns, in which each unit contributes equally to the system’s overall statistical characteristics of diversity, despite its individual units having measurably different levels of diversity and endemism. This systemization presents a highly efficient descriptive model that can possibly be interpreted as a form of natural classification. An additional analysis of the same mode is described here, in which the seven-region model of the distribution of mammal families’ spatial affinities is shown to closely approach a most-probable-state arrangement, as assessed through combinatorics, raising some important questions about …

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Genetic And Environmental Contributions To Wolbachia-Induced Cytoplasmic Incompatibility, Kelley Van Vaerenberghe Jan 2023

Genetic And Environmental Contributions To Wolbachia-Induced Cytoplasmic Incompatibility, Kelley Van Vaerenberghe

Graduate Student Theses, Dissertations, & Professional Papers

Maternally-transmitted Wolbachia infect the cells of most insect species, but their frequencies in host populations vary. While much of their success can be attributed to their ability to manipulate host reproduction, these manipulations are context-dependent, varying due to several biotic and abiotic factors. Wolbachia’s most common manipulation, cytoplasmic incompatibility (CI), is a conditional sterility phenotype where male-female host compatibility depends on their infection status. Specifically, CI occurs when infected males produce modified sperm that cause increased embryonic lethality unless the female carries a similar infection. Rescuing their eggs from CI increases the relative fitness of infected females, promoting Wolbachia spread …

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Plant Sentience? Between Romanticism And Denial: Science, Miguel Segundo-Ortin, Paco Calvo Jan 2023

Plant Sentience? Between Romanticism And Denial: Science, Miguel Segundo-Ortin, Paco Calvo

Animal Sentience

A growing number of non-human animal species are being seriously considered as candidates for sentience, but plants are either forgotten or explicitly excluded from these debates. In our view, this is based on the belief that plant behavior is hardwired and inflexible and on an underestimation of the role of plant electrophysiology. We weigh such assumptions against the evidence to suggest that it is time to take seriously the hypothesis that plants, too, might be sentient. We hope this target article will serve as an invitation to investigate sentience in plants with the same rigor as in non-human animals.

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Quantitative Song Variety In Relation To Genotype In A Hybridizing Chickadee Population, Shelby Madison Palmer Jan 2023

Quantitative Song Variety In Relation To Genotype In A Hybridizing Chickadee Population, Shelby Madison Palmer

Graduate Theses/Dissertations

The Black-capped chickadee (Poecile atricapillus) and Carolina chickadee (P. carolinensis) are North American songbird species that hybridize in a narrow contact zone stretching latitudinally from New Jersey to Kansas, USA. The association between genetic ancestry and song type in this hybrid zone has been studied independently several times and found to be minimal or absent, likely due to the influence of cultural transmission on learned song in the oscine passerine clade to which the chickadees belong. Despite this, the song of both species remains remarkably distinct in allopatry, suggesting a genetic constraint on certain qualities of …

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Between Choice And Compulsion: An Examination And Critique Of The Evolution Of 'Original Sin', Matthew James Wynn Jan 2023

Between Choice And Compulsion: An Examination And Critique Of The Evolution Of 'Original Sin', Matthew James Wynn

Graduate Theses/Dissertations

“Why are we the way that we are?” is one of the hardest questions to answer because it requires grasping the origin of human beings. This has left philosophers and theologians in century-long debates on forming a “cosmogony of ontology” (i.e., how the origin of the universe informs the human condition). The concept, “original sin” was developed by a North African theologian named Augustine (354 – 430 CE). Augustine’s reading of Genesis 3, and inaccurate translation of Romans 5:12, taught that a person is born morally culpable for a fault antecedent to their existence. This way of thinking about the …

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