title: How the temperate world was colonised by bindweeds: biogeography of the Convolvuleae (Convolvulaceae).
abstract: BACKGROUND
  At a global scale, the temperate zone is highly fragmented both between and within hemispheres. This paper aims to investigate how the world's disjunct temperate zones have been colonised by the pan-temperate plant group Convolvuleae, sampling 148 of the c. 225 known species. We specifically determine the number and timing of amphitropical and transoceanic disjunctions, investigate the extent to which disjunctions in Convolvuleae are spatio-temporally congruent with those in other temperate plant groups and determine the impact of long-distance dispersal events on diversification rates.
  
  
  RESULTS
  Eight major disjunctions are observed in Convolvuleae: two Northern Hemisphere, two Southern Hemisphere and four amphitropical. Diversity in the Southern Hemisphere is largely the result of a single colonisation of Africa 3.1-6.4 Ma, and subsequent dispersals from Africa to both Australasia and South America. Speciation rates within this monophyletic, largely Southern Hemisphere group (1.38 species Myr(-1)) are found to be over twice those of the tribe as a whole (0.64 species Myr(-1)). Increased speciation rates are also observed in Calystegia (1.65 species Myr(-1)).
  
  
  CONCLUSIONS
  The Convolvuleae has colonised every continent of the world with a temperate biome in c. 18 Myr and eight major range disjunctions underlie this broad distribution. In keeping with other temperate lineages exhibiting disjunct distributions, long-distance dispersal is inferred as the main process explaining the patterns observed although for one American-Eurasian disjunction we cannot exclude vicariance. The colonisation of the temperate zones of the three southern continents within the last c. 4 Myr is likely to have stimulated high rates of diversification recovered in this group, with lineage accumulation rates comparable to those reported for adaptive radiations.
authors.affiliation: Plant Biodiversity Research, Technische Universität München, Emil-Ramann Strasse 2, 85354, Freising, Germany. tom.mitchell@tum.de.
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Mitchell
authors.affiliation: Department of Plant Sciences, University of Oxford, South Parks Road, Oxford, OX1 3RB, UK. bethwilliams822@gmail.com.
authors.forename: Bethany R M
authors.initials: BR
authors.lastname: Williams
authors.affiliation: Department of Plant Sciences, University of Oxford, South Parks Road, Oxford, OX1 3RB, UK. jriwood@hotmail.com.
authors.forename: John R I
authors.initials: JR
authors.lastname: Wood
authors.affiliation: Royal Botanic Garden Edinburgh, 20A Inverleith Row, Edinburgh, EH3 5LR, UK. d.harris@rbge.org.uk.
authors.forename: David J
authors.initials: DJ
authors.lastname: Harris
authors.affiliation: Department of Plant Sciences, University of Oxford, South Parks Road, Oxford, OX1 3RB, UK. robert.scotland@plants.ox.ac.uk.
authors.forename: Robert W
authors.initials: RW
authors.lastname: Scotland
authors.affiliation: Department of Life Sciences, The Natural History Museum, Cromwell Road, London, SW7 5BD, UK. m.carine@nhm.ac.uk.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Carine
mesh_terms: D000349:Africa; D027722:Convolvulaceae / Q000502:physiology*; D058865:Introduced Species; D010802:Phylogeny; D058974:Phylogeography; D013020:South America