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Full-Text Articles in Life Sciences
Cellular And Developmental Insights Into The Early Evolution Of Muscle, Jeffrey J. Colgren
Cellular And Developmental Insights Into The Early Evolution Of Muscle, Jeffrey J. Colgren
Electronic Theses and Dissertations
Whereas a great deal has been learned about the molecular underpinnings of morphological evolution in animals, much less is known about the origin of novel cell and tissue types. During the time in which the earliest animal lineages were diversifying, fundamental cell and tissue types, such as muscles, arose. Sponges are one of two animal lineages that lack muscles, yet they undergo coordinated full body contractions. Whereas the signaling processes have been studied, the physical mechanisms of contraction are completely uncharacterized. The main purpose of this work is to understand the primary contractile tissue of the sponge Ephydatia muelleri, …
Land Use Influences Along Elevation Gradient On Macroinvertebrate Communities, Brittany Sprout
Land Use Influences Along Elevation Gradient On Macroinvertebrate Communities, Brittany Sprout
Electronic Theses and Dissertations
Land use activities have caused disturbances that affect the quality of freshwater ecosystems worldwide. How the influences of land use along an environmental gradient and the associated environmental variables that may influence stream diversity and function is unclear. We address these issues by studying biodiversity, abundance, and functional diversity of macroinvertebrates across different land types along a gradient in Colorado, USA. We also address how diversity may change along an elevation gradient by analyzing previously published macroinvertebrate research. We found evidence that land use and disturbance are stronger explanations of changes in macroinvertebrate communities, rather than elevation. Functional trait patterns …
The Role Of Cognition In Sexual Signals And Mate Choice Decisions, Ross Minter
The Role Of Cognition In Sexual Signals And Mate Choice Decisions, Ross Minter
Electronic Theses and Dissertations
Cognitive ability varies dramatically among individuals, yet the manner in which this variation affects reproduction has rarely been investigated. Here, we asked 1) whether male sexual signals reflect cognitive ability and whether females prefer males with superior cognitive abilities, and 2) whether female cognition affects male and female mating decisions? We addressed these questions in a mutual mate choice system, threespine sticklebacks (Gasterosteus aculeatus). We tested cognitive performance by presenting the males and females with a novel task (a barrier to food) to evaluate problem-solving abilities and learning. We found that males that problem solve have elaborate sexual …
Host Use And Geographic Variation In Fall Webworms (Hyphantria Cunea), Katrina J. Loewy
Host Use And Geographic Variation In Fall Webworms (Hyphantria Cunea), Katrina J. Loewy
Electronic Theses and Dissertations
Host use in herbivores is determined by a variety of ecological drivers, including bottom-up and top-down selective pressures such as host abundance, host plant quality, and parasitism pressure. If the relative importance and strength of interactions among these selective conditions change over an herbivore’s geographic range, local patterns of host use should change in response, evident in differing diet breadths. The fall webworm (Hyphantria cunea) is a widespread, polyphagous moth with two color morphs, red and black-headed. In the eastern United States, fall webworms feed on dozens of plant species and previous research demonstrated that host plant abundance …
Fire-Derived Charcoal Along An Ecological Gradient In The Colorado Front Range, Christopher William Licata
Fire-Derived Charcoal Along An Ecological Gradient In The Colorado Front Range, Christopher William Licata
Electronic Theses and Dissertations
Terrestrial ecosystems are shaped by natural disturbances such as wildland fire. In the intermountain western United States, forests, shrub and grasslands adapt to repeated fires. An important long-term legacy of wildland fires is black C (BC) commonly referred to as char or charcoal. Black C is a recalcitrant C form that has been long known to influence soil physical, chemical, and biological processes that they vary across landscapes and over time. The objective of this research is to address two key areas in the emerging field of ecosystem BC research; 1) how much BC as charcoal C is formed per …
Quantifying Soil And Groundwater Chemistry In Areas Invaded By Tamarix Spp. Along The Middle Rio Grande, New Mexico, Michelle Kelly Ohrtman
Quantifying Soil And Groundwater Chemistry In Areas Invaded By Tamarix Spp. Along The Middle Rio Grande, New Mexico, Michelle Kelly Ohrtman
Electronic Theses and Dissertations
Tamarix spp. (a.k.a. saltcedar, tamarisk) invasion is considered a major ecological threat at both national and global levels, with supposed impacts on soil and water chemistry. One of the most often cited mechanisms of ecosystem change by Tamarix is through its ability to deposit salty exudates and salt-rich leaf litter. The degree to which Tamarix relates to elevated soil and groundwater salinity, however, has not been adequately quantified, especially in the context of environmental factors that may also influence salinity. If Tamarix does elevate localized salinity by means of uptake, concentration and exudation by plant tissues, then we might expect …