Parasite phylogenetics can offer windows into the cryptic evolutionary history of hosts, often highlighting events that are not recorded by the phylogenetics of the host. Pikas (small lagomorphs) host a diverse parasite community comprising endoparasites (e.g., coccidians, nematodes, and cestodes) and ectoparasites (e.g., fleas and mites). Phylogenetic analysis of pika endoparasites has revealed pikas evolved in Asia and colonized North America in two waves, and that contact between these two pika lineages allowed parasites to be transferred from one lineage to another and to survive the extinction of their original host. To uncover these cryptic histories, understanding the biogeography of parasites is essential. Comparisons of the distribution of the pika endoparasites with those of pika ectoparasites in North America revealed widespread and relictual lineages of both. Phylogenies of North American pika fleas mirrored the patterns seen in pika cestodes, with relictual populations of fleas belonging to lineages that arrived in North America before the arrival of extant pikas. The discovery of Margopsylla tolli from collared pikas in the Northwest Territories of Canada provides additional context to the history of pikas in North America. Margopsylla tolli parasitizes both Ochotona collaris in Alaska and northern Canada and Ochotona hyperborea in eastern Siberia and Manchuria. The presence of this species on both sides of the Bering Strait is suggestive of late Pleistocene contact between O. collaris and O. hyperborea, supporting previous findings from pika pinworms.
","abstract_html":"<p>Parasite phylogenetics can offer windows into the cryptic evolutionary history of hosts, often highlighting events that are not recorded by the phylogenetics of the host. Pikas (small lagomorphs) host a diverse parasite community comprising endoparasites (e.g., coccidians, nematodes, and cestodes) and ectoparasites (e.g., fleas and mites). Phylogenetic analysis of pika endoparasites has revealed pikas evolved in Asia and colonized North America in two waves, and that contact between these two pika lineages allowed parasites to be transferred from one lineage to another and to survive the extinction of their original host. To uncover these cryptic histories, understanding the biogeography of parasites is essential. Comparisons of the distribution of the pika endoparasites with those of pika ectoparasites in North America revealed widespread and relictual lineages of both. Phylogenies of North American pika fleas mirrored the patterns seen in pika cestodes, with relictual populations of fleas belonging to lineages that arrived in North America before the arrival of extant pikas. The discovery of <em>Margopsylla tolli</em> from collared pikas in the Northwest Territories of Canada provides additional context to the history of pikas in North America. <em>Margopsylla tolli </em>parasitizes both <em>Ochotona collaris </em>in Alaska and northern Canada and <em>Ochotona hyperborea</em> in eastern Siberia and Manchuria. The presence of this species on both sides of the Bering Strait is suggestive of late Pleistocene contact between <em>O. collaris</em> and <em>O. hyperborea</em>, supporting previous findings from pika pinworms.</p>","abstract_has_math":false,"creators":["Pletcher, Josh"],"institution":null,"degree_name":"Master of Science","degree_level":"Thesis","degree_discipline":"Biology","degree_department":null,"school":null,"contributors":["Kurt Galbreath"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2026,"date_issued":"2026-05-01T07:00:00Z","date_published":"2026-05-01T07:00:00Z","updated_at":"2026-07-24T03:24:38Z","subjects":["pika","Ochotona","Geusibia","Margopsylla tolli","flea","Siphonaptera","Ctenophyllus","phylogenetics","Cestoda","Schizorchis","Biodiversity","Entomology","Evolution","Genomics","Molecular Genetics","Paleobiology","Zoology"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://commons.nmu.edu/theses/925","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Kurt Galbreath"]},{"key":"dc:creator","label":"Author","values":["Pletcher, Josh"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.available","label":"Dc Date Available","values":["2026-04-02T07:00:00Z"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Biology"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["pika","Ochotona","Geusibia","Margopsylla tolli","flea","Siphonaptera","Ctenophyllus","phylogenetics","Cestoda","Schizorchis","Biodiversity","Entomology","Evolution","Genomics","Molecular Genetics","Paleobiology","Zoology"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://commons.nmu.edu/theses/925"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Parasite phylogenetics can offer windows into the cryptic evolutionary history of hosts, often highlighting events that are not recorded by the phylogenetics of the host. Pikas (small lagomorphs) host a diverse parasite community comprising endoparasites (e.g., coccidians, nematodes, and cestodes) and ectoparasites (e.g., fleas and mites). Phylogenetic analysis of pika endoparasites has revealed pikas evolved in Asia and colonized North America in two waves, and that contact between these two pika lineages allowed parasites to be transferred from one lineage to another and to survive the extinction of their original host. To uncover these cryptic histories, understanding the biogeography of parasites is essential. Comparisons of the distribution of the pika endoparasites with those of pika ectoparasites in North America revealed widespread and relictual lineages of both. Phylogenies of North American pika fleas mirrored the patterns seen in pika cestodes, with relictual populations of fleas belonging to lineages that arrived in North America before the arrival of extant pikas. The discovery of Margopsylla tolli from collared pikas in the Northwest Territories of Canada provides additional context to the history of pikas in North America. Margopsylla tolli parasitizes both Ochotona collaris in Alaska and northern Canada and Ochotona hyperborea in eastern Siberia and Manchuria. The presence of this species on both sides of the Bering Strait is suggestive of late Pleistocene contact between O. collaris and O. hyperborea, supporting previous findings from pika pinworms.
"]},{"key":"dc:title","label":"Title","values":["The Hitchhiker's Guide to the Host: Fleas and the History of Pikas in North America"]}]}],"canonical_facts":{"dc:contributor":["Kurt Galbreath"],"dc:creator":["Pletcher, Josh"],"dc:date.available":["2026-04-02T07:00:00Z"],"dc:description.abstract":["Parasite phylogenetics can offer windows into the cryptic evolutionary history of hosts, often highlighting events that are not recorded by the phylogenetics of the host. Pikas (small lagomorphs) host a diverse parasite community comprising endoparasites (e.g., coccidians, nematodes, and cestodes) and ectoparasites (e.g., fleas and mites). Phylogenetic analysis of pika endoparasites has revealed pikas evolved in Asia and colonized North America in two waves, and that contact between these two pika lineages allowed parasites to be transferred from one lineage to another and to survive the extinction of their original host. To uncover these cryptic histories, understanding the biogeography of parasites is essential. Comparisons of the distribution of the pika endoparasites with those of pika ectoparasites in North America revealed widespread and relictual lineages of both. Phylogenies of North American pika fleas mirrored the patterns seen in pika cestodes, with relictual populations of fleas belonging to lineages that arrived in North America before the arrival of extant pikas. The discovery of Margopsylla tolli from collared pikas in the Northwest Territories of Canada provides additional context to the history of pikas in North America. Margopsylla tolli parasitizes both Ochotona collaris in Alaska and northern Canada and Ochotona hyperborea in eastern Siberia and Manchuria. The presence of this species on both sides of the Bering Strait is suggestive of late Pleistocene contact between O. collaris and O. hyperborea, supporting previous findings from pika pinworms.
"],"dc:identifier":["https://commons.nmu.edu/theses/925"],"dc:subject":["pika","Ochotona","Geusibia","Margopsylla tolli","flea","Siphonaptera","Ctenophyllus","phylogenetics","Cestoda","Schizorchis","Biodiversity","Entomology","Evolution","Genomics","Molecular Genetics","Paleobiology","Zoology"],"dc:title":["The Hitchhiker's Guide to the Host: Fleas and the History of Pikas in North America"],"thesis:degree_discipline":["Biology"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["Master of Science"]},"updated_at":"2026-07-24T03:24:38Z"}