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Full-Text Articles in Life Sciences

Variation In Salamander Tail Regeneration Is Associated With Genetic Factors That Determine Tail Morphology, Gareth J. Voss, D. Kevin Kump, John A. Walker, S. Randal Voss Jul 2013

Variation In Salamander Tail Regeneration Is Associated With Genetic Factors That Determine Tail Morphology, Gareth J. Voss, D. Kevin Kump, John A. Walker, S. Randal Voss

Biology Faculty Publications

Very little is known about the factors that cause variation in regenerative potential within and between species. Here, we used a genetic approach to identify heritable genetic factors that explain variation in tail regenerative outgrowth. A hybrid ambystomatid salamander (Ambystoma mexicanum x A. andersoni) was crossed to an A. mexicanum and 217 offspring were induced to undergo metamorphosis and attain terrestrial adult morphology using thyroid hormone. Following metamorphosis, each salamander’s tail tip was amputated and allowed to regenerate, and then amputated a second time and allowed to regenerate. Also, DNA was isolated from all individuals and genotypes were determined ...


Testing Subspecies Limits In Monardella Villosa, Taylor Mclaughlin Crow Mr. Jun 2013

Testing Subspecies Limits In Monardella Villosa, Taylor Mclaughlin Crow Mr.

Master's Theses and Project Reports

Several subspecies of Monardella villosa (California Coyote Mint) have been distinguished on the basis of leaf thickness, shape, and trichome characteristics, yet many intermediates are known. We investigated morphological differences in natural populations of two subspecies (M. v. subsp. villosa and M. v. subsp. franciscana) in the Scott Creek watershed, north of Davenport, in Santa Cruz County, CA. Monardella villosa subsp. franciscana grows in coastal scrub in gulches and ocean terraces whereas subsp. villosa grows at more protected inland sites. Morphological difference between subspecies may be adaptations to these different habitats. I grew plants in a common garden at Cal ...


Fossil Trachemys (Testudines: Emydidae) From The Late Hemphillian Of Eastern Tennessee And Its Implications For The Evolution Of The Emydidae, Steven E. Jasinski May 2013

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 ...


Understanding Biodiversity: The Importance Of Sexual Dimorphism In The Micro- And Macroevolution Of Hummingbirds, Chelsea Marie Berns Jan 2013

Understanding Biodiversity: The Importance Of Sexual Dimorphism In The Micro- And Macroevolution Of Hummingbirds, Chelsea Marie Berns

Graduate Theses and Dissertations

ABSTRACT

For centuries, biologists have asked "why are there so many species, and why do we see such magnificent biological diversity?" This dissertation addresses this question by examining sexual size and shape dimorphism hummingbird bills at both a micro and macroevolutionary scale. Specifically, I quantify sexual size and shape dimorphism of bill morphology of 269 species of hummingbirds and begin with a species-level study to find that community structure might be a driving factor in the evolution of sexual size dimorphism in 2 sister species of hummingbirds, and the presence of sexual shape dimorphism in one of those species.

I ...


Differential Jumping Performance In Newly Metamorphosed Blanchard's Cricket Frogs, Acris Blanchardi (Anura: Hylidae), From Fish- And Invertebrate-Dominated Ponds, Taylor L. Hall, Daniel Saenz, Matthew Kwiatkowski Jan 2013

Differential Jumping Performance In Newly Metamorphosed Blanchard's Cricket Frogs, Acris Blanchardi (Anura: Hylidae), From Fish- And Invertebrate-Dominated Ponds, Taylor L. Hall, Daniel Saenz, Matthew Kwiatkowski

Faculty Publications

Organisms that adopt phenotypically plastic anti-predator strategies during larval stages may incur fitness costs later in development. These costs are typically difficult to define in many species. The difficulty of identifying ecological trade-offs may result from experimental comparisons that do not adequately mirror naturally occurring predator-prey relatioships. To examine this, we captured 61 newly metamorphosed Acris blanchardi from ponds dominated either by fish or invertebrate predators. These predators are known to induce alternate phenotypic anti-predator responses at the larval stage. We use jumping performance as a measure of post-metamorphic fitness, and compared the morphological traits and jumping ability of frogs ...


Worms, Nematoda, Scott Lyell Gardner Jan 2013

Worms, Nematoda, Scott Lyell Gardner

Scott Gardner Publications & Papers

Nematodes are the most speciose phylum of metazoa on earth. Not only do they occur in huge numbers as parasites of all known animal groups, but also they are found in the soils, as parasites of plants, and in large numbers in the most extreme environments, from the Antarctic dry valleys to the benthos of the ocean. They are extremely variable in their morphological characteristics, with each group showing morphological adapta­tions to the environment that they inhabit. Soil-dwelling forms are extremely small; many marine species have long and complex setae; and parasitic species man­ifest amazingly great reproductive potential ...


Nutrient Availability Affects Flowering Rate But Has Limited Influence On Morphology Of The Hooded Pitcher Plant, Sarracenia Minor., Justin M. Lemmons Jan 2013

Nutrient Availability Affects Flowering Rate But Has Limited Influence On Morphology Of The Hooded Pitcher Plant, Sarracenia Minor., Justin M. Lemmons

UNF Graduate Theses and Dissertations

Carnivorous plants perform as both producers and consumers. Botanical carnivory has evolved in sunny, moist, nutrient-poor environments, and the primary nutrient supplied by prey is proposed to be nitrogen. There is a trade-off between carnivorous and photosynthetic structures which corresponds to degree of carnivory expression and available nutrients. This study was conducted on the hooded pitcher plant, Sarracenia minor, which is a facultative wetland plant and Florida-threatened species. Sarracenia minor is considered a specialist myrmecophage and ants characterize the majority of attracted and captured prey. Ants not only provide nutritional benefit, but also protection against herbivory. A natural population of ...