The ubiquitous mountain hare mitochondria: multiple introgressive hybridization in hares, genus Lepus

• Published in: Philosophical Transactions of the Royal Society B: Biological Sciences
• Main Authors: Alves, Paulo C., Melo-Ferreira, José, Freitas, Helder, Boursot, Pierre
• Other Authors: CIBIO/UP, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto = University of Porto, Departamento de Zoologia e Antropologia, Faculdade de Ciências da Universidade do Porto (FCUP), Universidade do Porto = University of Porto-Universidade do Porto = University of Porto, Institut des Sciences de l'Evolution de Montpellier (UMR ISEM), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Montpellier (UM)-Institut de recherche pour le développement IRD : UR226-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2008
• Subjects: hybridization; mitochondrial DNA introgression; hares; Iberian Peninsula; selection; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; Arctic; Lepus timidus; mountain hare
• Online Access: https://hal.science/halsde-00454765; https://doi.org/10.1098/rstb.2008.0053

International audience Climatic oscillations during the glaciations forced dramatic changes in species distributions, such that some presently temperate regions were alternately occupied by temperate and arctic species. These species could have met and hybridized during climatic transitions. This phenomenon happened for three hare species present in Iberia ( Lepus granatensis, Lepus europaeus and Lepus castroviejoi), which display high frequencies of mitochondrial DNA ( mtDNA) from Lepus timidus, an arctic/ boreal species presently extinct in Iberia. Here, we extend our previous geographical survey to determine whether the distribution of this mtDNA lineage extends beyond the northern half of the Iberian Peninsula, where it is found at high frequencies. We also review the taxonomy, distribution and molecular phylogeny of the genus Lepus. The phylogenetic inference reveals the presence of L. timidus- like mtDNA in several other hare species in Asia and North America, suggesting that the mitochondrial introgression observed in Iberia might be generalized. Comparison with the available nuclear gene phylogenies suggests that introgression could have happened repeatedly, possibly during different climatic transitions. We discuss demographic and adaptive scenarios that could account for the repetition in time and space of this spectacular phenomenon and suggest ways to improve our understanding of its determinants and consequences. Such high levels of introgressive hybridization should discourage attempts to revise hare taxonomy based solely on mtDNA.