The order Rodentia is the most abundant and successful group of mammals, and it has been a focal point of attention for compar ative and evolutionary biologists for many years. In addition, rodents are the most commonly used experimental mammals for bio medical research, and they have played a central role in investi gations of the genetic and molecular mechanisms of speciation in mammals. During recent decades, a tremendous amount of new data from various aspects of the biology of living and fossil rodents has been accumulated by specialists from different disciplines, ranging from molecular biology to paleontology. Paradoxically, our understanding of the possible evolutionary relationships among different rodent families, as well as the possible affinities of rodents with other eutherian mammals, has not kept pace with this information "explosion. " This abundance of new biological data has not been incorporated into a broad synthesis of rodent phylo geny, in part because of the difficulty for any single student of rodent evolution to evaluate the phylogenetic significance of new findings from such diverse disciplines as paleontology, embryology, comparative anatomy, molecular biology, and cytogenetics. The origin and subsequent radiation of the order Rodentia were based primarily on the acquisition of a key character complex: specializations of the incisors, cheek teeth, and associated mus culoskeletal features of the jaws and skull for gnawing and chewing.

Oliver P. Pearson’s studies on mammalian biology remain standard reading for ecologists, physiologists, taxonomists, and biogeographers. Reflecting this, the papers gathered here continue to expand our understanding of the ecology and evolution of subterranean mammals, and of ecology, taxonomy, and biogeography of Neotropical mammals, a group that was central to the latter half of Pearson’s career.

Since the subject of arenaviruses was visited by Current Topics in Microbiology and Immunology 14 years ago, enormous advances have been made in this area. The receptor for several arenaviruses, alpha-dystroglycan, was identified, the replication strategy of these viruses was decoded, and application of a reverse genetics system for studying viral gene function and viral biology is well underway. In addition to reviewing these advances, Volume I includes discussion of arenaviral molecular phylogeny, reservoirs in rodents and clinical diseases caused by both new world and old world arenaviruses.

A valuable resource for the latest research on rodents, highlighting links across palaeontology, developmental biology, functional morphology, phylogenetics and biomechanics.