ABSTRACT
Introduction....................................................................................................................................21 Evolutionary history.....................................................................................................................22 Glacial refugia and historical genetics: peering into the past ...............................................25 Postglacial dispersal......................................................................................................................25 Secondary contact among refugial groups ...............................................................................27 Genetic structure of modern populations.................................................................................28 Species interactions and anthropogenic disturbances ............................................................32 Research needs...............................................................................................................................33 Conclusion......................................................................................................................................33 References .......................................................................................................................................33
Evidence suggests that lake trout likely evolved in response to environmental changes caused by glaciation events during the Pleistocene era. Following the retreat of the last ice sheets, lake trout recolonized their present range from multiple refugia. Populations in Boreal Shield lakes are descended from at least six refugial groups, with the greatest contributions from Mississippian and Atlantic sources. Secondary contact among these separate lineages was a significant source of genetic diversity, enabling adaptation to local environments.
