This thesis addresses the consequences of the last glaciation on the distribution and genetic diversity of arctic flora. The principal aim is to infer the full-glacial and postglacial migrational history of Dryas integrifolia M. Vahl. (Rosaceae) from the intraspecific phylogeny of cpDNA haplotypes along with pollen and macrofossil distribution data. The results suggest that four refugia existed during the last glaciation and that each served as significant sources of recolonization when the ice retreated. The two most important refugia are located in the northwestern Arctic (Beringia and the High Arctic), with two other refugia located southeast of the ice sheet and along the coastal regions of the eastern Arctic. High genetic substructure among populations is likely attributable to past vicariance and recent recolonization events, whereas high local diversity is probably indicative of recolonization from several sources and high gene flow in recent time.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.20880 |
| Date | January 1997 |
| Creators | Tremblay, Nicolas-Olivier R. |
| Contributors | Schoen, Daniel J. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Biology.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001609821, proquestno: MQ44301, Theses scanned by UMI/ProQuest. |
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