BERINGIAN BIOGEOGRAPHY: PATTERNS OF INTERCONTINENTAL DISPERSAL AND THE STRUCTURING OF A HOLARCTIC TAPEWORM GENUS

<p>The opening and closing of the Bering Land Bridge due to Pleistocene climate fluctuations facilitated the exchange of taxa between the Palearctic and Nearctic. While many studies have worked toward elucidating the role of Beringia in assembling northern faunas, relatively little work has focused on parasites. Here I examine the number and direction of transberingian colonization events within the Holarctic tapeworm genus, <em>Arostrilepis </em>Mas-Coma & Tenora, 1997. I performed maximum likelihood and multi-locus coalescent phylogenetic reconstructions using mitochondrial and nuclear DNA sequences. Biogeographic ancestral range estimations were conducted on the resulting species phylogeny. My systematic reconstructions reveal as many as 16 <em>Arostrilepis</em> lineages that could represent previously undescribed species-level diversity. Biogeographic estimates strongly indicate that <em>Arostrilepis</em> experienced at least four eastward transberingian dispersals associated with <em>Microtus, Myodes, </em>and <em>Lemmus </em>hosts. Comparing the <em>Arostrilepis </em>colonization history with the pattern of its host associations shows that host-switching is prevalent in its history particularly following the Nearctic colonization associated with <em>Microtus </em>voles. Evidence also suggests that during the colonization event associated with lemmings,<em> </em>the direction of <em>Arostrilepis </em>colonization may have been counter to that of its hosts. These results highlight the complex history of faunal assembly associated with Beringian mammal-parasite assemblages.</p>

Name thesis:degree_name

Master of Science

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Biology

Year dc:date.available

2017

Author dc:creator

• Haas, Genevieve M

Contributors dc:contributor

• Kurt Galbreath

• Biogeography
• Beringia
• Hymenolepididae
• Arostrilepis
• Arvicolinae
• Holarctic
• Biology

Repository record dc:identifier

https://commons.nmu.edu/theses/150

OAI identifier oai:identifier

oai:commons.nmu.edu:theses-1177