Testing hypotheses on disjunctions present in the primarily woody Boraginales: Ehretiaceae, Cordiaceae, and Heliotropiaceae, inferred from ITS1 sequence data

Publication Type:Journal Article
Year of Publication:2004
Authors:Gottschling, M, Diane, N, Hilger, HH, Weigend, M
Journal:Int. J. Plant Sci.
Volume:165
Pagination:S123–S135
Keywords:{ITS1}, distribution, divergence rate, Kimura two-parameter distances, long-distance dispersal, paleoclimate, phylogeography, vicariance.
Abstract:

Hypotheses on the origin of the current distribution patterns and bicontinental disjunctions of Cordiaceae, Ehretiaceae, and Heliotropiaceae (Primarily Woody Boraginales) are tested by pairwise comparison of Kimura two-parameter distances. Estimated absolute dates of fossils and geological events (plate tectonics, climate changes) were used to calibrate a molecular clock. A mid-Cretaceous origin of the Primarily Woody Boraginales is proposed with an initial diversification in South America. Plate tectonics appear to play a minor role in their phylogeography. Most disjunctions are best explained by the rare events of long-distance dispersal because of the widespread occurrence of drupaceous fruits and their potential for endozoochoria. Furthermore, migrations and extinctions might have played a considerable role in the formation of the current distribution patterns.

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith