The goal of this project is to reconstruct relationships within Simaroubaceae, a small, poorly understood family of tropical and temperate trees and shrubs. To accomplish this goal DNA sequence data from five gene regions, and appropriate analytical computer software will be used. The resulting phylogeny (history of relationships) will be used in conjunction with morphological characteristics of family members, fossils of fruits and leaves, current geographical distributions, and past climate and tectonic activity, to elucidate historical migrations and diversification of the Simaroubaceae during the past 65 million years. Analyses will detect shifts in speciation rates, and correlate these with the evolution of key morphological innovations and cross-continental migrations.
This project will contribute to a growing body of knowledge concerning the long and complex histories of many tropical plant families, and further clarify the diversification of the tropical biota on a global basis. The phylogeny of the Simaroubaceae has the potential to inform conservation policy for regions in which some of the rarer members of the family occur, by highlighting their genetic uniqueness. Morphological and molecular data will also be incorporated into a summary of Simaroubaceae to appear in Kubitzki's 'Families and Genera of Vascular Plants', and a page on the Tree of Life web project (www.tolweb.org).