Abstract Detail

Systematics Section / ASPT

Donoghue, Michael J. [1], Winkworth, Richard C. [1].

Historical biogeography of Viburnum (Adoxaceae, Dipsacales).

Our recent phylogenetic studies on Viburnum set the stage for an analysis of historical biogeography. Here we focus on intercontinental disjunctions involving twelve well-supported clades, and especially on disjunctions betweens the Old and New Worlds. Seven of these twelve clades are confined to one major region – four to Asia, and three to the New World; two others are present in Asia and Europe, one in Asia and North America, and two occur in Asia, Europe, and North America. Asia is the most diverse region both in terms of species and the number of major clades represented. In contrast, Latin America has high species diversity, but with the exception of one species these all belong to a single clade. Dispersal-Vicariance analyses imply that Viburnum originated and initially diversified within Asia, spreading later to Europe and to the New World. We identified at least four Old World/New World disjunctions. Two of these fall between major clades and are presumably older: one separates the Old World Lantana clade from the New World Lentago clade, and the other the Old World Tinus and the New World Porphyrodontotinus clades. The two other disjunctions occur within clades and appear to be younger: one is between the New World V. acerifolium and related Old World Lobodontotinus species, and the other between the New World V. lantanoides and related Old World Pseudotinus species. Members of the older New World clades were presumably well established in North America before the arrival of V. acerifolium and V. lantanoides (and probably also members of the Opulus clade). Preliminary age estimates imply that movements to the New World were probably through Beringia. Overall, Viburnum suggests a complicated picture of Northern Hemisphere biogeography, with similar disjunctions established at different times in different clades.

1 - Yale University, Department of Ecology and Evolutionary Biology, P.O. Box 208105, New Haven, Connecticut, 06520-8105, USA

Keywords:
divergence time estimates
disjunction
dipersal and vicariance
Northern Hemisphere biogeography
Viburnum
multigene analyses
historical biogeography.

Presentation Type: Paper
Session: 18-9
Location: Cottonwood A (Snowbird Center)
Date: Monday, August 2nd, 2004
Time: 3:15 PM
Abstract ID:693