Evolutionary relationships among organisms are central to research in the biological sciences. Understanding the history of branching and divergence through the history of a group of organisms must precede an understanding of their function, ecology, geographic distribution, even their relevance for medical research. Drs. Robert Sokal and F. James Rohlf have, for the past three decades, pioneered the use of computers for reconstructing evolutionary relationships among organisms based on morphological and molecular data sets. Several different approaches have been proposed for reconstructing phylogenies (e.g., maximum parsimony, maximum likelihood, overall similarity). Past work by Sokal and Rohlf has shown that under different circumstances, each of these alternate methods produces the most accurate and stable reconstruction of a computer- generated branching history. They now propose to develop new methods with which investigators can select the most appropriate tool for analyzing real data, for which the underlying branching history is unknown. The methods and advice to be developed will have a wide audience, including systematists working on all organisms, and functional morphologists and biogeographers, for whom evolutionary relationships provide the framework for their research.
