Publication Type:Thesis
Year of Publication:2023
Authors:L. Mario D'Alessio
Academic Department:Graduate College - (Programme -Ecology, Evolution, and Conservation Biology)
Number of Pages:39 pp
University:University of Illinois Urbana-Champaign
City:Urbana, Illinois
Thesis Type:Master of Science in Ecology, Evolution, and Conservation Biology

Parasitism is an extremely common and widespread life-strategy, thus understanding the evolution of parasites with hosts remains an integral topic in evolutionary biology. Feather lice (Phthiraptera: Ischnocera) are a group of permanent ectoparasitic insects that spend their entire life cycle on their host, only being mobile when transmitting between individual hosts such as parents and offspring. The Brueelia-complex is an incredibly speciose group of feather lice found mostly on passerine birds across the world. There are already over 400 species in this group that have been described, with many more left to be discovered or synonymized. Noted for its strong host-specificity, the Brueelia-complex serves as a choice model to study coevolution and co-diversification. To study these processes a phylogenetic framework is needed. To achieve this, I first analyzed over 1000 gene sequences using concatenated and coalescent methods to construct well-supported phylogenies for genera within the Brueelia-complex that help resolve disputed generic relationships. I then performed cophylogenetic analyses with avian hosts that revealed distinct patterns of host-switching of lice a.) within suboscine birds, and b.) in and out of passerine hosts. A biogeographical analysis suggests a New World origin of the Brueelia complex and subsequent diversification into other continents. Lastly, phylogenetic analyses of bacterial endosymbionts provide the first insight into the relationships among Sodalis symbionts within the Brueelia-complex. Together, my results provide the most current assessment of the relationships among the many genera within the Brueelia-complex and insight into their coevolutionary history with avian hosts and symbiotic bacteria

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