Phylogeny and biogeography of the sandalwoods (Santalum, Santalaceae): repeated dispersals throughout the Pacific

• DOI: 10.3732/ajb.94.6.1028
• Publication Date: 2008-02-29T22:42:44Z
• Authors: Danica T. Harbaugh; Bruce G. Baldwin
• Keywords: Monophyly; Santalum album; Insular biogeography; Maximum parsimony

Results of the first genus-wide phylogenetic analysis for Santalum (Santalaceae), using a combination 18S-26S nuclear ribosomal (ITS, ETS) and chloroplast (3' trnK intron) DNA sequences, provide new perspectives on relationships biogeographic patterns among widespread economically important sandalwoods. Congruent trees based maximum parsimony, likelihood, Bayesian methods support an origin in Australia at least five putatively bird-mediated, long-distance dispersal events out Australia, with two colonizations Melanesia, Hawaiian Islands, one Juan Fernandez Islands. The data also best available evidence plant Islands to Bonin eastern Polynesia. Inability reject rate constancy ITS evolution use fossil-based calibrations yielded estimates timing speciation colonization Pacific, dates 1.0-1.5 million yr ago (Ma) 0.4-0.6 Ma onset diversification lineages. results indicate that previously recognized sections Polynesica, Santalum, Solenantha, Australian species S. lanceolatum, freycinetianum are not monophyletic need taxonomic revision, which is currently being pursued.