Hinchliff, Cody , Roalson, Eric .
The latitudinal diversity gradient: evidence from the sedges.
The latitudinal gradient in species richness is one of the oldest and most enigmatic topics in modern biology. Species richness decreases rapidly with distance from the equator, and despite numerous hypotheses about why this might occur, a satisfactory explanation remains elusive. To address this question, we use the globally important sedge family (Cyperaceae) to test an important prediction: that rates of diversification may vary meaningfully with distance from the equator. This prediction follows from the theoretical work proposed by Wiens and Donoghue in 2004, known as the tropical conservatism hypothesis. We used GenBank data as well as novel genetic sequences to reconstruct the phylogeny of over 1,000 species of Cyperaceae, and estimated character-dependent diversification rates on the resulting phylogenetic trees to test the correlation between diversification rate and distance from the equator. Preliminary evidence suggests that these rates vary widely among lineages within the family, indicating the importance of several major species radiations (incl. the genus Carex) in the creation of global patterns of sedge diversity.
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1 - Washington State University, School of Biological Sciences, 239C Abelson Hall, Pullman, WA, 99164-4236
2 - Washington State University, School of Biological Sciences, 332 Abelson Hall, Pullman, WA, 99164-4236
latidinal diversity gradient
Presentation Type: Oral Paper:Papers for Sections
Location: Portland Room/Chase Park Plaza
Date: Monday, July 11th, 2011
Time: 1:30 PM