A new individual-based spatial approach for identifying genetic discontinuities in natural populations

• Published in: Molecular Ecology
• Main Authors: Manel, S., Berthoud, F., Bellemain, E., Gaudeul, M., Luikart, G., Swenson, J. E., Waits, L. P., Taberlet, P.
• Other Authors: Laboratoire d'Ecologie Alpine (LECA), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry ), Laboratoire de physique et modélisation des milieux condensés (LPM2C), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Department of Ecology and Natural Resource Management, Norwegian University of Life Sciences (NMBU), Department of Fish and Wildlife Resources, University of Idaho Moscow, USA
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2007
• Subjects: assignment test; genetic discontinuity; moving windows; multilocus genotype; spatial genetics; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; [SDV.BID]Life Sciences [q-bio]/Biodiversity; [SDV.EE]Life Sciences [q-bio]/Ecology; environment; Ursus arctos
• Online Access: https://hal.archives-ouvertes.fr/halsde-00276500; https://doi.org/10.1111/j.1365-294X.2007.03293.x

International audience The population concept is central in evolutionary and conservation biology, but identifying the boundaries of natural populations is often challenging. Here, we present a new approach for assessing spatial genetic structure without the a priori assumptions on the locations of populations made by adopting an individual-centred approach. Our method is based on assignment tests applied in a moving window over an extensively sampled study area. For each individual, a spatially explicit probability surface is constructed, showing the estimated probability of finding its multilocus genotype across the landscape, and identifying putative migrants. Population boundaries are localized by estimating the mean slope of these probability surfaces over all individuals to identify areas with genetic discontinuities. The significance of the genetic discontinuities is assessed by permutation tests. This new approach has the potential to reveal cryptic population structure and to improve our ability to understand gene flow dynamics across landscapes. We illustrate our approach by simulations and by analysing two empirical datasets: microsatellite data of Ursus arctos in Scandinavia, and amplified fragment length polymorphism (AFLP) data of Rhododendron ferrugineum in the Alps.