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A Comparative Study Of Isolation In Headwater Fishes, Bjorn Victor Schmidt
A Comparative Study Of Isolation In Headwater Fishes, Bjorn Victor Schmidt
Dissertations
Headwater resident fishes may be prone to a high rate of population fragmentation within river networks because large streams have habitat conditions outside of their preferred ecological niche and may limit gene flow in the dendritic ecological network. To investigate patterns of population structure, asymmetrical gene flow, and influences on genetic distance and isolation from connecting habitat pathways, species specific ecological traits, and basin scale characteristics, a multi-species, multi-regional study was performed. Six headwater species of fish from four taxonomic groupings were sampled for genetic material in three regions of paired neighbor drainages and then genotyped for eight microsatellite loci. …
Population Demographics And Genetics Of Spix's Disk-Winged Bat: Insights Regarding Survival, Mate Choice, Gene Flow And Effective Population Size, Michael Buchalski
Population Demographics And Genetics Of Spix's Disk-Winged Bat: Insights Regarding Survival, Mate Choice, Gene Flow And Effective Population Size, Michael Buchalski
Dissertations
Simultaneous study of the demographics and genetics of populations are relatively rare within the literature, despite insights their combined use offers regarding the life history, ecology, and evolution of species. Here I take a comprehensive approach, using capture-recapture data, polymorphic microsatellite markers, and various modeling techniques to examine the demographics and genetics of multiple local populations of Spix’s disk-winged bat (Thyroptera tricolor) in southwestern Costa Rica. T. tricolor is a highly gregarious, neotropical bat species known to form kin-based social groups with high retention of offspring of both sexes. The implications of this highly unusual social structure for …
Host-Parasite Interactions In Galapagos Seabirds, Iris Ilena Levin
Host-Parasite Interactions In Galapagos Seabirds, Iris Ilena Levin
Dissertations
Parasites exhibit a wide range of life history strategies that contribute to different dispersal abilities, host specialization, transmission modes, life-cycle complexity and population structure. Understanding dispersal rates in hosts and parasites is instrumental in defining the scale at which coevolution may be occurring. In order to better understand how and when parasites move between different hosts, I studied a seabird – Hippoboscid fly ectoparasite (and vector) – Haemosporidian parasite system in the Galapagos Islands. I began by describing the Haemosporidian parasites of Galapagos seabirds, discovering a Plasmodium species parasite in Galapagos Penguins (Sphensicus mendiculus), and a new clade of Hippoboscid-vectored …
Population Genetics Of Island Endemics: Neutral And Major Histocompatibility Loci, Jennifer Lynn Bollmer
Population Genetics Of Island Endemics: Neutral And Major Histocompatibility Loci, Jennifer Lynn Bollmer
Dissertations
Island archipelagoes are ideal for the study of microevolutionary forces due to their multiple, closely related but geographically disjunct populations. I used both neutral and major histocompatibility complex (MHC) loci to determine the population genetic structures of bird species endemic to the Galapagos Islands. MHC molecules recognize foreign pathogens in the body, and these loci are known for their high degree of genetic variability maintained by natural selection. Small island populations are predicted to have reduced genetic variability due to the effects of genetic drift; however, selection may be strong enough to prevent the loss of variability at MHC loci. …