Phylogeography of northern North America with insights from paleontological, geological, and molecular data
Bain, John F .
Haplotype diversity and reticulate evolution in Packera (Asteraceae: Senecioneae).
The genus Packera is a well-defined lineage comprising 50+ species that are widely distributed in North America and differ in their distribution, breeding system, soil and ecological preferences. Most species are found in western North America, where cpDNA data suggests the presence of two main lineages and haplotype diversity patterns in numerous species of Packera highlight the importance within the complex of refugial survival followed by cycles of range expansion and hybridization. High levels of intrapopulational cpDNA haplotype diversity characterize most of the species so far examined and various other factors besides hybridization and introgression may play a role in determining diversity patterns. Packera subnuda is an alpine species whose range extends from California to the mountains of southern Alberta. Peripheral populations at the northern and eastern edge of its range are fixed for cpDNA haplotypes that are very different from those found throughout most of the rest of the species range, while ITS repeat type diversity patterns distinguish eastern and northern populations. Taxa restricted to serpentine soils (P. hesperia and P. eurycephala var. lewisrosei) differ from each other both in terms of cpDNA haplotypes present and related haplotype diversity patterns.
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1 - University of Lethbridge, Biological Sciences, 4401 University Drive, Lethbridge, Alberta, T1K 3M4, Canada
Presentation Type: Symposium or Colloquium Presentation
Location: Room 4/Woodward
Date: Monday, July 28th, 2008
Time: 10:00 AM