Molecular Ecology and Evolution
Grady, Ben R. , Sytsma, Kenneth .
Sorting out relationships in the 'capitate clade' of Eriogonum (Polygonaceae): Evolution in the Great Basin and beyond .
Species-level phylogenetic inference in plants can be complicated by many issues (e.g. introgression, incomplete lineage sorting, polyploidy); the causes of genealogical discordance have been well documented. Many of these processes are apparent in the evolutionary history of Eriogonum (Polygonaceae). Here we demonstrate incongruent genealogical histories within the 'capitate clade' of Eriogonum. Extensive ingroup sampling reveals signatures of a recent, rapid radiation. Few species within this group exhibit reciprocal monophyly based on our chloroplast and nuclear gene trees, although the Genealogical Sorting Index (GSI) is used to test the extent of non-monophyly of species. Specific cases of discordance are highlighted with examples from both rare and widespread species in this clade. For example, Eriogonum shockleyi, a widespread member of the 'capitate clade', shows patterns of recent hybridization with other species in this group. Chloroplast capture is evident from plastid intron sequences, and nuclear regions show similar patterns with E. shockleyi. Certain sub-clades within this radiation show strong geographic clustering within floristic sections of the Intermountain Region of the western United States. Spatial and temporal patterns of current species distributions are investigated in a phylogenetic framework, to illuminate the biogeographic history of this group.
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1 - University Of Wisconsin-Madison, Botany, 430 Lincoln Dr., Madison, WI, 53706, USA
2 - University of Wisconsin-Madison, Department of Botany, 430 Lincoln Dr., Madison, WI, 53706, USA
Great Basin Desert.
Presentation Type: Oral Paper:Papers for Topics
Location: Westminster Room/Chase Park Plaza
Date: Monday, July 11th, 2011
Time: 4:15 PM