Supertree Analysis of the Plant Family Fabaceae

Abstract The “Tree-of-Life” is a national and international project to collect information aboutthe origin, evolution, and diversity of organisms, with the goal of producing a tree of all life onEarth (Pennisi, 2003). The obstacles to achieving this goal are many. From questions relatedto the kinds and number of data to be used, to building that phylogeny, to the methodologicaland computational resources required to analyze the massive amounts of data expected to benecessary to bring this to fruition. The development of efficient methods for phylogeneticanalyses of thousands (hundreds of thousands) of taxa has become increasingly important tothis endeavor, as well as somewhat controversial. Supertree construction is one of thesemethods proposed for reconstructing phylogenies on a large scale (Bininda-Emonds, 2004).This method combines phylogenetic trees (topologies), which overlap taxonomically, ratherthan the primary data, to produce a larger tree using standard methods of analyses such asparsimony. This method also has the advantage of being able to incorporate trees derived frommany different kinds of data into tree estimation. For the study presented here, acomprehensive literature search identified 185 phylogenetic trees published since 1984 on theplant family Fabacaeae (the “legumes”). Of these, 68 trees were chosen for supertree analysisand were divided into three major groups, two of which correspond to strongly-supportedmonophyletic groups identified by recent studies that sampled extensively across the family andare based on standard phylogenetic analyses of single data sets (e.g. gene sequences).Supertrees of taxa that correspond to the three subfamilies Mimosoideae, Caesalpinioideae, andPapilionoideae will be presented here.