Abstract Detail

Systematics Section/ASPT

Spriggs, Elizabeth [1], Clement, Wendy [2], Sweeney, Patrick [3], Edwards, Erika [4], Donoghue, Michael [5].

Patterns and mysteries in Viburnum diversification.

We conducted a wide array of diversification analyses using increasingly well-sampled molecular phylogenies of Viburnum, and generating “complete” trees with missing species included based on morphological traits.  In addition to focusing attention on the importance of sampling and other methodological issues (e.g., AIC thresholds; ability to detect nested radiations), these analyses consistently highlight three regions in the tree where there seem to have been significant increases in diversification rate.  These increases may relate to particular characters (e.g., fruit color) and/or to topographic/environmental heterogeneity.  In several cases, we also detected increases at deeper nodes in the tree that may result from “trickle-down” effects.  For example, although extrafloral nectaries (EFNs) are sometimes associated with high diversification, this may simply reflect the fact that the EFN clade contains two of the consistently identified major radiations.  There are also several places where elevated extinction rates seem likely.  We postulate that Viburnum diversified originally in tropical environments, subsequently radiated in temperate and boreal biomes, and has been suffering increased extinction in the tropics where we now see dying embers of an earlier phase of evolution.

1 - Yale University, Department of Ecology and Evolutionary Biology, 21 Sachem Street, Environmental Science Center, 358C, New Haven, CT, 06511
2 - The College Of New Jersey, Biology, 2000 Pennington Road, Department Of Biology, Ewing, NJ, 08638, USA
3 - Yale University Herbarium, Peabody Museum of Natural History, P.O. Box 208118, New Haven, CT, 06520-8118, USA
4 - Brown University, Box G-W, 80 Waterman St, Providence, RI, 02912, USA
5 - Yale University, Department Of Ecology And Evolutionary Biology, 21 Sachem Street, PO BOX 208105, New Haven, CT, 06511, USA

Keywords:
diversification
Dipsacales
Speciation
extinction
Key Innovation.

Presentation Type: Oral Paper:Papers for Sections
Session: 45
Location: River Fork/Grove
Date: Wednesday, July 30th, 2014
Time: 4:45 PM
Number: 45013
Abstract ID:332
Candidate for Awards:None