title: High migration rates shape the postglacial history of amphi-Atlantic bryophytes.
abstract: Paleontological evidence and current patterns of angiosperm species richness suggest that European biota experienced more severe bottlenecks than North American ones during the last glacial maximum. How well this pattern fits other plant species is less clear. Bryophytes offer a unique opportunity to contrast the impact of the last glacial maximum in North America and Europe because about 60% of the European bryoflora is shared with North America. Here, we use population genetic analyses based on approximate Bayesian computation on eight amphi-Atlantic species to test the hypothesis that North American populations were less impacted by the last glacial maximum, exhibiting higher levels of genetic diversity than European ones and ultimately serving as a refugium for the postglacial recolonization of Europe. In contrast with this hypothesis, the best-fit demographic model involved similar patterns of population size contractions, comparable levels of genetic diversity and balanced migration rates between European and North American populations. Our results thus suggest that bryophytes have experienced comparable demographic glacial histories on both sides of the Atlantic. Although a weak, but significant genetic structure was systematically recovered between European and North American populations, evidence for migration from and towards both continents suggests that amphi-Atlantic bryophyte population may function as a metapopulation network. Reconstructing the biogeographic history of either North American or European bryophyte populations therefore requires a large, trans-Atlantic geographic framework.
authors.affiliation: Institute of Botany, University of Liège, B22 Sart Tilman, Liège, Belgium. aurelie_desamore@hotmail.com.|Department of Zoology, Swedish Museum of Natural History, Box 50007, SE-104 05, Stockholm, Sweden. aurelie_desamore@hotmail.com.
authors.forename: Aurélie
authors.initials: A
authors.lastname: Désamoré
authors.affiliation: Institute of Botany, University of Liège, B22 Sart Tilman, Liège, Belgium.|Island Ecology and Evolution Research Group, Instituto de Productos Naturales y Agrobiología (IPNA-CSIC), Tenerife, Canary Islands, 38206, Spain.|Centre for Ecology, Evolution and Environmental Changes and Platform for Enhancing Ecological Research & Sustainability, Universidade dos Açores, 9700-042, Angra do Heroísmo, Terceira, Açores, Portugal.
authors.forename: Jairo
authors.initials: J
authors.lastname: Patiño
authors.affiliation: Department of Evolutionary Biology and Ecology, Université libre de Bruxelles, Campus du Solbosch, Avenue F.D. Roosevelt 50, 1050, Bruxelles, Belgium.
authors.forename: Patrick
authors.initials: P
authors.lastname: Mardulyn
authors.affiliation: Department of Biology, University of Florida, Box 118525, Gainesville, FL, 32611-8525, USA.
authors.forename: Stuart F
authors.initials: SF
authors.lastname: Mcdaniel
authors.affiliation: Institute of Botany, University of Liège, B22 Sart Tilman, Liège, Belgium.
authors.forename: Florian
authors.initials: F
authors.lastname: Zanatta
authors.affiliation: Institute of Botany, University of Liège, B22 Sart Tilman, Liège, Belgium.|SciLifeLab Stockholm, Department of Ecology, Environment and Plant Sciences, Stockholm University, Tomtebodav. 23a, 171 21, Solna, Stockholm, Sweden.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Laenen
authors.affiliation: Institute of Botany, University of Liège, B22 Sart Tilman, Liège, Belgium.|Island Ecology and Evolution Research Group, Instituto de Productos Naturales y Agrobiología (IPNA-CSIC), Tenerife, Canary Islands, 38206, Spain.
authors.forename: Alain
authors.initials: A
authors.lastname: Vanderpoorten
mesh_terms: D001499:Bayes Theorem; D005075:Biological Evolution; D044002:Bryophyta / Q000145:classification* / Q000235:genetics; D005060:Europe; D014644:Genetic Variation; D005828:Genetics, Population; D046448:Ice Cover; D009656:North America; D010802:Phylogeny; D063148:Plant Dispersal; D011156:Population Density
keywords: approximate Bayesian computation; bryophytes; dispersal; glacial cycle; postglacial recolonization; refugium