THE CASE OF TARSIER HEMOGLOBIN

by other methods of ancestral reconstruction. Critics also argue that it is not possible to determine which of several alternative topologies, differing by a small number of NR's, most closely reflects cladogeny since the statistical significance of the NR score differences is unknown. A careful investigation of the method of these critics reveals that their method is nonrigorous, nonreplicable and produces erroneous results. The need for rigorous, automated systems of data analysis in studies of molecular evolution is made apparent, particularly in light of the voluminous nature of the data. We here describe a series of parsimony tests conducted with globin amino acid sequence data, focusing on the position of Tarsius within Primates, in order to illustrate the importance of interpreting NR score differences within a context which includes the number of lineages represented in a data set, the density of the lineages in particular regions of a dendrogram and the exact nature of the changes attributed to specific NR savings. Analyzed within the context of these changing parameters, small NR score differences between alternative topologies can be meaningful and do produce results with significant confidence. The phylogenetic relationship of Tarsius to Anthropoidea, as well as other important issues in primate systematics, are expected to be greatly clarified with the gathering and rigorous analysis of nucleotide sequence data which can resolve the difficulties presented by convergent evolution and paralogous gene lines. [Tarsier phylogeny; maximum parsimony methodology; molecular evolution; primate evolution; molecular anthropology; hemoglobin phylogeny.]