Genetic consequences of Pleistocene range shifts: contrast between the Arctic, the Alps and the East African mountains

• Published in: Molecular Ecology
• Main Authors: Ehrich, D., Gaudeul, M., Assefa, A., Koch, M. A., Mummenhoff, K., Nemomissa, S., Consortium, I., Brochmann, C.
• Other Authors: National Centre for Biosystematics (NCB), University of Oslo (UiO), Laboratoire d'Ecologie Alpine (LECA), Université Joseph Fourier - Grenoble 1 (UJF)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS), Department of Biology, Addis Ababa University (AAU), Biodiversity and Plant Systematics, Universität Heidelberg Heidelberg
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2007
• Subjects: AFLP; Arabis alpina; genetic diversity; leading-edge colonization; refugia; European alps; population-structure; molecular evidence; alpine plants; aflp data; ice ages; phylogeography; colonization; quaternary; speciation; geo; envir; Arctic; Climate change; North Atlantic
• Online Access: https://doi.org/10.1111/j.1365-294X.2007.03299.x; https://hal.archives-ouvertes.fr/halsde-00283755

International audience In wide-ranging species, the genetic consequences of range shifts in response to climate change during the Pleistocene can be predicted to differ among different parts of the distribution area. We used amplified fragment length polymorphism data to compare the genetic structure of Arabis alpina, a widespread arctic-alpine and afro-alpine plant, in three distinct parts of its range: the North Atlantic region, which was recolonized after the last ice age, the European Alps, where range shifts were probably primarily altitudinal, and the high mountains of East Africa, where the contemporary mountain top populations result from range contraction. Genetic structure was inferred using clustering analyses and estimates of genetic diversity within and between populations. There was virtually no diversity in the vast North Atlantic region, which was probably recolonized from a single refugial population, possibly located between the Alps and the northern ice sheets. In the European mountains, genetic diversity was high and distinct genetic groups had a patchy and sometimes disjunct distribution. In the African mountains, genetic diversity was high, clearly structured and partially in accordance with a previous chloroplast phylogeography. The fragmented structure in the European and African mountains indicated that A. alpina disperses little among established populations. Occasional long-distance dispersal events were, however, suggested in all regions. The lack of genetic diversity in the north may be explained by leading-edge colonization by this pioneer plant in glacier forelands, closely following the retracting glaciers. Overall, the genetic structure observed corresponded to the expectations based on the environmental history of the different regions.