The lessons of genomic evolution are gradually revealing themselves through studies of population divergence, genetic differentiation, and disease pattern of natural populations. Phylogenetic analyses of three carnivore orders (Felidae, Ursidae, and Procyonidae) have produced chronological hierarchies that form the basis of taxonomic distinction and adaptation during the carnivore radiations. Lessons of historic and ongoing epidemics and ensuing genomic adaptations are critical to interpreting the functional context of genome organization. Population screens of baseline medical genetics and reproductive physiologies offer recurring new insight into biological strategies that influence species survival and provide a fuller understanding of the interaction of species genomes and their biological environment. Using the methods of molecular genetics to monitor sequence variation, several components that influence stability of natural populations have been discovered. The consequences of close inbreeding in several endangered species is most dramatically documented in the case of the Florida puma. A full-length sequence of a novel lentivirus isolated from pumas has been determined. Several examples of inter-species transfer of human T-cell lymphotropic virus-I (HTLV-I) have been inferred from phylogenetic reconstruction.