9629592 WHITE One of the goals of systematic biology is to reconstruct the historical (phylogenetic) relationships among organisms. A number of analytical methods have been devised that will produce phylogenetic reconstructions. When identical sets of data obtained from organisms are evaluated by the different reconstruction methods, differing phylogenies sometimes result. Because the true phylogenetic relationships of organisms in nature are not known, it is difficult to assess which of the different reconstructions best approximates their actual history. In the laboratory, rapidly-changing organisms can be raised in which the true history of each lineage, and its characteristics, can be precisely known and manipulated. Phylogenies reconstructed by the various analytical methods in use in systematic biology can be compared with the known history, and in this way the efficiency of each method in discovering the correct or true phylogeny can be evaluated. In this study, Mary White will produce lineages of bacterial viruses, including Bacteriophage T7 and Bacteriophage phiX 174. The histories of these lineages will be precisely known, as will their characteristics, monitored by molecular methods such as DNA sequencing and restriction enzyme mapping. The molecular characteristics will provide the data from which phylogenies will be reconstructed and compared against the known histories. Knowledge gained from this work will lead to a better understanding of the proper application of existing phylogenetic methods to recover the history of organisms in nature, and to refinements and improvements in these methods. The project will be used as a tool for teaching students, in classroom and laboratory settings, about such diverse topics as mutations and mutagens, virology, molecular biology and biotechnology, and systematics, and will be instrumental in developing discovery-based approaches to the teaching of these areas of science. Students will be involved in all stages of the research.
