Mitochondrial genomics and Northwestern Atlantic population genetics of marine annelids

dc.contributor.author Jennings, Robert M.
dc.coverage.spatial Northwestern Atlantic
dc.date.accessioned 2007-06-22T18:11:08Z
dc.date.available 2007-06-22T18:11:08Z
dc.date.issued 2005-09
dc.description Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution September 2005 en
dc.description.abstract The overarching goal of this thesis was to investigate marine benthic invertebrate phylogenetics and population genetics, focused on the phylum Annelida. Recent expansions of molecular methods and the increasing diversity of available markers have allowed more complex and fine-scale questions to be asked at a variety of taxonomic levels. At the phylogenetic level, whole mitochondrial genome sequencing of two polychaetes (the deep-sea tubeworm Riftia pachyptila and the intertidal bamboo worm Clymenella torquata) supports the placement of leeches and oligochaetes within the polychaete radiation, in keeping with molecular evidence and morphological reinvestigations. This re-interpretation, first proposed by others, synonomizes "Annelida" and "Polychaeta", and lends further support to the inclusion of echiurids, siboglinids (previously called vestimentiferans) within annelids, and sipunculans as close allies. The complete mt-genome of C. torquata was then rapidly screened to obtain markers useful in short timescale population genetics. Two quickly evolving mitochondrial markers were sequenced from ten populations of C. torquata from the Bay of Fundy to New Jersey to investigate previous hypotheses that the Cape Cod, MA peninsula is a barrier to gene flow in the northwest Atlantic. A barrier to gene flow was found, but displaced south of Cape Cod, between Rhode Island and Long Island, NY. Imposed upon this pattern was a gradient in genetic diversity presumably due to previous glaciation, with northern populations exhibiting greatly reduced diversity relative to southern sites. These trends in C. torquata, combined with other recent short time scale population genetic research, highlight the lack of population genetics models relevant to marine benthic invertebrates. To this end, I constructed a model including a typical benthic invertebrate life cycle, and described the patterns of genetic differentiation at the juvenile and adult stages. Model analysis indicates that selection operating at the postsettlement stage may be extremely important in structuring genetic differentiation between populations and life stages. Further, it demonstrates how combined genetic analysis of sub-adult and adult samples can provide more information about population dynamics than either could alone. en
dc.description.sponsorship Financial support was provided by an Academic Programs Office fellowship, a CICOR fellowship and research grant, and a National Science Foundation research grant. en
dc.format.mimetype application/pdf
dc.identifier.citation Jennings, R. M. (2005). Mitochondrial genomics and Northwestern Atlantic population genetics of marine annelids [Doctoral thesis, Massachusetts Institute of Technology and Woods Hole Oceanographic Institution]. Woods Hole Open Access Server. https://doi.org/10.1575/1912/1714
dc.identifier.doi 10.1575/1912/1714
dc.identifier.uri https://hdl.handle.net/1912/1714
dc.language.iso en_US en
dc.publisher Massachusetts Institute of Technology and Woods Hole Oceanographic Institution en
dc.relation.ispartofseries WHOI Theses en
dc.subject Benthic animals en_US
dc.subject Annelida en_US
dc.subject Animal population genetics en_US
dc.subject Larvae en_US
dc.title Mitochondrial genomics and Northwestern Atlantic population genetics of marine annelids en
dc.type Thesis en
dspace.entity.type Publication
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relation.isAuthorOfPublication.latestForDiscovery b6f5dd05-bf25-47dd-bcf1-95dd82a07290
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