Around the pole: evolution of sub-Antarctic Ranunculus

• Published in: Journal of Biogeography
• Main Authors: Lehnebach, Carlos A., Winkworth, Richard C., Becker, Matthias, Lockhart, Peter J., Hennion, Françoise
• Other Authors: Museum of New Zealand - Te Papa Tongarewa, Institute of Fundamental Sciences Palmerston, Massey University, Unitec Institute of Technology, IGZ, Leibnitz Institute of Vegetable and Ornamental Crops, Ecosystèmes, biodiversité, évolution Rennes (ECOBIO), Université de Rennes (UR)-Institut Ecologie et Environnement - CNRS Ecologie et Environnement (INEE-CNRS), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS), The Museum of New Zealand Te Papa Tongarewa and Massey University Research Fund financially supported this research. The Centre National de la Recherche Scientifique (CNRS) (PICS programme ‘AntarctBiodiv’ led by F.H.) and the Universite de Rennes 1 also provided support.Work on the Iles Kerguelen and Archipel Crozet was supported by the Institut Polar Francais (IPEV) (Programmes 136 led by M. Lebouvier and 1116 by F.H.). This research is linked to the CNRS Zone-Atelier Antarctique and the Scientific Committee on Antarctic Research (SCAR) programmesAntEco and AnT-ERA.
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2017
• Subjects: dispersal; divergence time estimates; ecomorphology; historical biogeography; phylogenetic biogeography; Ranunculus; sub-Antarctic islands; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; Antarctic; Austral; New Zealand; Antarc*
• Online Access: https://univ-rennes.hal.science/hal-01507695; https://doi.org/10.1111/jbi.12952

International audience Aim Despite an improved understanding of Southern Hemisphere plant biogeography, the origins and evolution of sub-Antarctic floras remain poorly studied. Here, we investigate the historical biogeography of sub-Antarctic representatives of the genus Ranunculus. We aimed to establish when and from where the sub-Antarctic ranunculi originated as well as to examine the extent to which ecomorphological traits explain contemporary biogeographical patterns. Location Southern temperate and sub-Antarctic zones. Methods We first estimated a dated phylogeny for Ranunculus using combined chloroplast and nuclear data for 53 accessions; divergence times were inferred based on three temporal calibrations. We then used non-parametric multidimensional scaling to evaluate the ecomorphological diversity of 67 austral ranunculi representing a combination of sub-Antarctic species and those restricted to lower latitude landmasses. Results Phylogenetic analyses indicated that several Ranunculus lineages have colonized the sub-Antarctic islands. Divergence time estimates suggest recent arrival from source areas in Australia, New Zealand or South America. Species exhibiting two distinct ecomorphological trait combinations occur in both sub-Antarctic and lower latitude habitats; the proportions of each combination differed significantly between these areas. Main conclusions Ranunculus has colonized the sub-Antarctic on several occasions, most often arriving from the lower latitude landmasses prior to the Last Glacial Maximum. Taken together our analyses suggest that chance effects are likely to have influenced species arrival. However, following arrival trait–environment interactions appear to have been important for the subsequent establishment and persistence of ranunculi in sub-Antarctic habitats.