The hares and rabbits belonging to the family Leporidae have a nearly worldwide distribution and approximately 72% of the genera have geographically restricted distributions. Despite several attempts using morphological, cytogenetic, and mitochondrial DNA evidence, a robust phylogeny for the Leporidae remains elusive. To provide phylogenetic resolution within this group, a molecular supermatrix was constructed for 27 taxa representing all 11 leporid genera. Five nuclear (SPTBN1, PRKCI, THY, TG, and MGF) and two mitochondrial (cytochrome b and 12S rRNA) gene fragments were analyzed singly and in combination using parsimony, maximum likelihood, and Bayesian inference. The analysis of each gene fragment separately as well as the combined mtDNA data almost invariably failed to provide strong statistical support for intergeneric relationships. In contrast, the combined nuclear DNA topology based on 3601 characters greatly increased phylogenetic resolution among leporid genera, as was evidenced by the number of topologies in the 95% confidence interval and the number of significantly supported nodes. The final molecular supermatrix contained 5483 genetic characters and analysis thereof consistently recovered the same topology across a range of six arbitrarily chosen model specifications. Twelve unique insertion-deletions were scored and all could be mapped to the tree to provide additional support without introducing any homoplasy. Dispersal-vicariance analyses suggest that the most parsimonious solution explaining the current geographic distribution of the group involves an Asian or North American origin for the Leporids followed by at least nine dispersals and five vicariance events. Of these dispersals, at least three intercontinental exchanges occurred between North America and Asia via the Bering Strait and an additional three independent dispersals into Africa could be identified. A relaxed Bayesian molecular clock applied to the seven loci used in this study indicated that most of the intercontinental exchanges occurred between 14 and 9 million years ago and this period is broadly coincidental with the onset of major Antarctic expansions causing land bridges to be exposed.

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The search for animal host origins of severe acute respiratory syndrome (SARS) coronavirus has so far remained focused on wildlife markets, restaurants and farms within China. A significant proportion of this wildlife enters China through an expanding regional network of illegal, international wildlife trade. We present the case for extending the search for ancestral coronaviruses and their hosts across international borders into countries such as Vietnam and Lao People's Democratic Republic, where the same guilds of species are found on sale in similar wildlife markets or food outlets. The three species that have so far been implicated, a viverrid, a mustelid and a canid, are part of a large suite of small carnivores distributed across this region currently overexploited by this international wildlife trade. A major lesson from SARS is that the underlying roots of newly emergent zoonotic diseases may lie in the parallel biodiversity crisis of massive species loss as a result of overexploitation of wild animal populations and the destruction of their natural habitats by increasing human populations. To address these dual threats to the long-term future of biodiversity, including man, requires a less anthropocentric and more interdisciplinary approach to problems that require the combined research expertise of ecologists, conservation biologists, veterinarians, epidemiologists, virologists, as well as human health professionals.

In the 1950s the myxoma virus was released into European rabbit populations in Australia and Europe, decimating populations and resulting in the rapid evolution of resistance. We investigated the genetic basis of resistance by comparing the exomes of rabbits collected before and after the pandemic. We found a strong pattern of parallel evolution, with selection on standing genetic variation favouring the same alleles in Australia, France and the United Kingdom. Many of these changes occurred in immunity-related genes, supporting a polygenic basis of resistance. We experimentally validated the role of several genes in viral replication and showed that selection acting on an interferon protein has increased its antiviral effect.

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