ASSEMBLING THE ANGIOSPERM TREE OF LIFE: PROGRESS AND FUTURE PROSPECTS

摘要

Over the past two decades there has been remarkable progress in resolving angiosperm phylogeny and patterns of evolution. Analyses of large, primarily plastid molecular data sets have revealed new insights into numerous historically contentious problems of deep-level angiosperm phylogeny, including relationships among "basal angiosperms" (not members ol either the eudicot or monocot clades), among clades ol Mesangiospernuw, and among major cladcs of eudicols. The same large data sets also have provided evidence for numerous rapid radiations throughout the evolution of angiosperms. The five lineages of Mesangiospermae, as well as most major core eudicot lineages, each likely arose within a narrow range of just a few million years. The rapid radiations in rosids (Rosidae) gave rise to angiosperm-dominated forests, which arc also associated with the diversification of ants, beetles, hemipterans, amphibians, and most extant ferns. Ongoing phylogcnetic analyses now routinely construct phylogenetic hypotheses encompassing thousands of taxa. Such trees enable us to take a broad phylogenetie perspective on character evolution, community assembly, and conservation. While the wealth of new sequence data continues to transform the study of angiosperm evolution, it also presents major computational and jnformatic challenges associated with the management and analysis of enormous data sets.