9714968 Zuckerkandl Complex organisms evolved from simpler ancestors through a process that included gene duplication and divergence. After duplication, the additional genes may have been relatively free to vary and take on new functions. This genetic flexibility has helped many organisms adapt to new environments. The DNA sequences in humans and other organisms provide a rich record from which a detailed evolutionary history of gene duplication and divergence may be deduced. This record will be mathematically analyzed in multicellular animals. The primary goal of this project is to help illuminate the history and genetic mechanisms of evolution, as well as the fundamental question of how complex organisms arose from simpler ancestors. Evolutionary relationships among genes, such as the descent of several modern genes from a single ancestral gene, provide a powerful basis for predicting molecular function and three-dimensional conformation. Thus, the basic knowledge gained from these evolutionary studies will be used in many other fields, including biochemistry, pharmacology, biomedical sciences, and biotechnology.