We are interested in the formation and maintenance of biological diversity, and the biotic and abiotic factors that contribute to these processes. This includes the investigation of large-scale climatic changes of the past and the present, and the impact of human actions on populations and species, but also the role of hybridization between and within species, and the mutational changes and rearrangements in genomes that have left their marks in the evolutionary trajectory. We focus on terrestrial mammals and birds as vertebrate model systems. However, we often extend our analyses also to the microbial commensals and pathogens of these vertebrates, and the more or less faithful evolutionary interactions with their hosts.