Browsing by Subject "Evolutionary biology"
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Item Multilocus assessment of population differentiation in Baja California birds: implications for community assembly and conservation(2014-08) Vazquez Miranda, HernanThis dissertation is an assessment of biological diversification at the community, species, and population levels from large continental scales in the Americas to small regions between Mexico and the U.S. using birds as a study system. In Chapter 1, I calculate when the avian community of the Baja California peninsula diverged from the mainland using mitochondrial and nuclear DNA sequences. I discovered that even though birds fly and could have arrived to the peninsula in independent dispersal waves, genetic estimates correspond to few events of diversification that correspond to historical barriers to gene flow and more recent ecologic scenarios. Additionally, I find evidence for recognizing four peninsular lineages as valid species, doubling the number of endemic birds in Baja California. Chapter 2 is a collaboration with Keith Barker. In it, we explore the continental diversification of wrens in the genus Campylorhynchus solving all evolutionary relationships by sequencing 23 genes and multiple individuals per lineage, developing a new metric for comparing all sorts of phylogenetic trees, and clarifying biogeographic and behavioral evolution aspects in the Neotropics. In Chapter 3, me and collaborators Kelly Barr, Craig Farquhar, and Robert Zink merge historic fire ecology and population genetics to understand how and when the black-capped vireo (Vireo atricapilla), went from being a historically common bird to being considered currently as endangered in its breeding grounds in the oak savannas of Oklahoma, Texas and northern Mexico. Five online supplementary files (OSFs) accompany this dissertation: the first file includes voucher numbers, geographic information, substitution models, used primers, and full likelihood values in Chapter 1 (OSF 1); the second file contains Bayesian trees ivand taxon pair distributions in Chapter 1 (OSF 2); the third file includes voucher numbers, evolutionary models, recombination tests, and primers used in Chapter 2 (OSF 3); the fourth file includes the randomization design in Chapter 2 (OSF 4); and the fifth file includes geographic information for all samples, primers, and multilocus phylogeny of vireos used in Chapter 3 (OSF 5).Item The Nature of Defense: Coevolutionary studies, ecological interaction, and the evolution of 'natural insecticides,' 1959-1983(2009-11) Mason Dentinger, Rachel NatalieThe field of "coevolutionary studies" became a vigorous domain of discovery in the 1960s, and its practitioners were direct inheritors of the modern evolutionary synthesis of the 1940s. They were also direct inheritors of a natural environment that seemed increasingly on the decline, thanks primarily to the destructive actions of humans. Thus, in my account, knowing--the pursuit of knowledge about the natural world--is inextricably interwoven with doing--the practical business of interacting with and altering the natural world, for better or worse. In the case of coevolutionary studies, the act of changing nature through technological intervention with chemical insecticides profoundly changed the way that biologists understood the natural world and the way that humans understood our own place in the natural world. In building this argument, I draw from the work of a variety of science studies scholars, especially environmental historians and historians of science who have examined the boundary between nature and technology, and so-called "basic" and "applied" sciences. I find that the values of control and intervention that are implicit in the applied sciences can have a direct, substantive effect on shaping the direction and form that basic science assumes. As a result, coevolutionary theory was, to a large extent, predicated on the role of humans as participants--interactors--in the very natural systems that coevolutionists strove to understand. To understand this dynamic, I analyze how methods, metaphors, and materials derived from the applied sciences of economic entomology and agronomy formed a foundation for coevolutionary studies. It is no coincidence that most of the scientists in this narrative were disciplinarily rooted in entomology or insect physiology, two fields where potent toxins aimed at destroying insects were of significant importance. These insect scientists were intimately familiar with the methods, metaphors, and materials used to intervene technologically in the operation of nature. Moreover, the model of chemical activity, of the causal agency of potent molecular tools, which dominated both insect physiology and economic entomology, shaped the model of biochemical interaction that drove early coevolutionary studies.