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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 roan antelope (Hippotragus equinus) is the second largest African antelope, distributed throughout the continent in sub-Saharan savannah habitat. Mitochondrial DNA (mtDNA) control region sequencing (401 bp, n = 137) and microsatellite genotyping (eight loci, n = 137) were used to quantify the genetic variability within and among 18 populations of this species. The within-population diversity was low to moderate with an average mtDNA nucleotide diversity of 1.9% and average expected heterozygosity with the microsatellites of 46%, but significant differences were found among populations with both the mtDNA and microsatellite data. Different levels of genetic resolution were found using the two marker sets, but both lent strong support for the separation of West African populations (samples from Benin, Senegal and Ghana) from the remainder of the populations studied across the African continent. Mismatch distribution analyses revealed possible past refugia for roan in the west and east of Africa. The West African populations could be recognized together as an evolutionarily significant unit (ESU), referable to the subspecies H. e. koba. Samples from the rest of the continent constituted a geographically more diverse assemblage with genetic associations not strictly corresponding to the other recognized subspecies.

Conventional wisdom predicts that sequential founder events will cause genetic diversity to erode in species with expanding geographic ranges, limiting evolutionary potential at the range margin. Here, we show that invasive European starlings (Sturnus vulgaris) in South Africa preserve genetic diversity during range expansion, possibly as a result of frequent long‐distance dispersal events. We further show that unfavourable environmental conditions trigger enhanced dispersal, as indicated by signatures of selection detected across the expanding range. This brings genetic variation to the expansion front, counterbalancing the cumulative effects of sequential founding events and optimizing standing genetic diversity and thus evolutionary potential at range margins during spread. Therefore, dispersal strategies should be highlighted as key determinants of the ecological and evolutionary performances of species in novel environments and in response to global environmental change.