Ecology and Evolutionary Biology Commons^™

Trade-Offs Between Morphology And Thermal Niches Mediate Adaptation In Response To Competing Selective Pressures, Stella F. Uiterwaal, Ian T. Lagerstrom, Thomas M. Luhring, Miranda E. Salsbery, John P. Delong

School of Biological Sciences: Faculty Publications

Abstract

The effects of climate change—such as increased temperature variability and novel predators—rarely happen in isolation, but it is unclear how organisms cope with multiple stressors simultaneously. To explore this, we grew replicate Paramecium caudatum populations in either constant or variable temperatures and exposed half to predation. We then fit thermal performance curves (TPCs) of intrinsic growth rate (r_max) for each replicate population (N = 12) across seven temperatures (10°C–38°C). TPCs of P. caudatum exposed to both temperature variability and predation responded only to one or the other (but not both), resulting in unpredictable outcomes. These changes in …

Plant Mitochondrial Genome Evolution And Structure Has Been Shaped By Double-Strand Break Repair And Recombination, Emily Wynn

School of Biological Sciences: Dissertations, Theses, and Student Research

Plant mitochondrial genomes are large but contain a small number of genes. These genes have very low mutation rates, but genomes rearrange and expand at significant rates. We propose that much of the apparent complexity of plant mitochondrial genomes can be explained by the interactions of double-strand break repair, recombination, and selection. One possible explanation for the disparity between the low mutation rates of genes and the high divergence of non-genes is that synonymous mutations in genes are not truly neutral. In some species, rps14 has been duplicated in the nucleus, allowing the mitochondrial copy to become a pseudogene. By …

Eight-Legged Encounters—Arachnids, Volunteers, And Art Help To Bridge The Gap Between Informal And Formal Science Learning, Eileen Hebets, Melissa Welch-Lazoritz, Pawl Tisdale, Patricia Wonch Hill

Eileen Hebets Publications

Increased integration and synergy between formal and informal learning environments is proposed to provide multiple benefits to science learners. In an effort to better bridge these two learning contexts, we developed an educational model that employs the charismatic nature of arachnids to engage the public of all ages in science learning; learning that aligns with the Next Generation Science Standards (NGSS Disciplinary Core Ideas associated with Biodiversity and Evolution). We created, implemented, and evaluated a family-focused, interactive science event—Eight-Legged Encounters (ELE)—which encompasses more than twenty modular activities. Volunteers facilitated participant involvement at each activity station and original …

Nocturnal Foraging Enhanced By Enlarged Secondary Eyes In A Net-Casting Spider, Jay A. Stafstrom, Eileen A. Hebets

Eileen Hebets Publications

Animals that possess extreme sensory structures are predicted to have a related extreme behavioral function. This study focuses on one such extreme sensory structure—the posterior median eyes of the net-casting spider Deinopis spinosa. Although past research has implicated the importance of vision in the nocturnal foraging habits of Deinopis, no direct link between vision in the enlarged eyes and nocturnal foraging has yet been made. To directly test the hypothesis that the enlarged posterior median eyes facilitate visually based nocturnal prey capture, we conducted repeated-measures, visual occlusion trials in both natural and laboratory settings. Our results indicate that D. …

Patterns Of Maximum Body Size Evolution In Cenozoic Land Mammals: Eco-Evolutionary Processes And Abiotic Forcing, Juha J. Saarinen, Alison G. Boyer, James H. Brown, Daniel P. Costa, S.K. Morgan Ernest, Alistair R. Evans, Mikael Fortelius, John L. Gittleman, Marcus J. Hamilton, Larisa E, Harding, Kari Lintulaakso, S. Kathleen Lyons, Jordan G. Okie, Richard M. Sibly, Patrick R. Stephens, Jessica Theodor, Mark D. Uhen, Felisa A. Smith

School of Biological Sciences: Faculty Publications

There is accumulating evidence that macroevolutionary patterns of mammal evolution during the Cenozoic follow similar trajectories on different continents. This would suggest that such patterns are strongly determined by global abiotic factors, such as climate, or by basic eco-evolutionary processes such as filling of niches by specialization. The similarity of pattern would be expected to extend to the history of individual clades. Here, we investigate the temporal distribution of maximum size observed within individual orders globally and on separate continents. While the maximum size of individual orders of large land mammals show differences and comprise several families, the times at …

The Roles Of Phenotypic Plasticity And Genotypic Specialization In High Altitude Adaptation, Danielle M. Tufts

School of Biological Sciences: Dissertations, Theses, and Student Research

In vertebrates living at high altitude, arterial hypoxemia may be ameliorated by reversible changes in the oxygen-carrying capacity of the blood (regulated by erythropoiesis) and/or changes in blood–oxygen affinity (regulated by allosteric effectors of hemoglobin function). These hematological traits often differ between taxa that are native to different elevational zones, but it is often unknown whether the observed physiological differences reflect fixed, genetically based differences or environmentally induced acclimatization responses (phenotypic plasticity). Here, we report measurements of hematological traits related to blood–O₂ transport in populations of deer mice (Peromyscus maniculatus) that are native to high- and low-altitude …