The role of chromosomal inversions in adaptation and speciation is controversial. Historically, inversions were thought to contribute to these processes either by directly causing hybrid sterility or by facilitating the maintenance of co-adapted gene complexes. Because inversions suppress recombination when heterozygous, a recently proposed local adaptation mechanism predicts that they will spr...

iii ACKNOWLEDGEMENTS I would like to express my deepest gratitude to the following people, without whom this thesis never would have been possible.-To the BCCER for your financial support, which greatly helped in acquiring greenhouse supplies and fuel for driving up and down Honey Run.-To my advisor and friend Dr. Chris Ivey, for hours of engaging scientific discussion and entertaining all of m...

1 Competition, trophic interactions and abiotic disturbances play important roles in governing plant population dynamics, yet few studies have addressed their relative contributions or interacting effects. 2 We used Life Table Response Experiment (LTRE) analysis, coupled with stochastic analyses, to examine how a major abiotic disturbance, flooding, influences the fitness and population growth ...

Understanding the genetic basis of reproductive isolation promises insight into speciation and the origins of biological diversity. While progress has been made in identifying genes underlying barriers to reproduction that function after fertilization (post-zygotic isolation), we know much less about earlier acting pre-zygotic barriers. Of particular interest are barriers involved in mating and...

Trypanosoma spp. of ground squirrels and most other rodents belong to the 3ubgenus Herpetosoma and have been recorded from approximately 80 to 90 different species of rodents throughout the world (Davis, 1952). They are often designated as leurisi-like after the type species, Trypanosoma (Herpetosoma) lewisi (Kent) Laveran & Mesnil. All are very similar in appearance and cannot be differentiate...

Sex-biased dispersal has profound impacts on a species' biology and several factors have been attributed to its evolution, including mating system, inbreeding avoidance, and social complexity. Sex-biased dispersal and its potential link to individual social interactions were examined in the Qinghai toad-headed agamid (Phrynocephalus vlangalii). We first determined the pattern of sex-biased disp...

Cranial endothermy evolved independently in lamnid sharks, billfishes and tunas, and is thought to minimize the effects of ambient temperature change on both vision and neural function during deep dives. The opah, Lampris guttatus, is a large epipelagic-mesopelagic predator that makes repeated dives into cool waters to forage. To determine if L. guttatus exhibits cranial endothermy, we measured...