title: Shifts in diversification rates linked to biogeographic movement into new areas: An example of a recent radiation in the Andes.
abstract: OBJECTIVE
  Clade-specific bursts in diversification are often associated with the evolution of key innovations. However, in groups with no obvious morphological innovations, observed upticks in diversification rates have also been attributed to the colonization of a new geographic environment. In this study, we explore the systematics, diversification dynamics, and historical biogeography of the plant clade Rhinantheae in the Orobanchaceae, with a special focus on the Andean clade of the genus Bartsia.
  
  
  METHODS
  We sampled taxa from across Rhinantheae, including a representative sample of Andean Bartsia species. Using standard phylogenetic methods, we reconstructed evolutionary relationships, inferred divergence times among the clades of Rhinantheae, elucidated their biogeographic history, and investigated diversification dynamics.
  
  
  RESULTS
  We confirmed that the South American Bartsia species form a highly supported monophyletic group. The median crown age of Rhinantheae was determined to be ca. 30 Myr, and Europe played an important role in the biogeographic history of the lineages. South America was first reconstructed in the biogeographic analyses around 9 Myr ago, and with a median age of 2.59 Myr, this clade shows a significant uptick in diversification.
  
  
  CONCLUSIONS
  Increased net diversification of the South American clade corresponds to biogeographic movement into the New World. This movement happened at a time when the Andes were reaching the necessary elevation to host an alpine environment. Although a specific route could not be identified with certainty, we provide plausible hypotheses to how the group colonized the New World.
authors.affiliation: Department of Biological Sciences, University of Idaho, 875 Perimeter MS 3051, Moscow, Idaho 83844-3051, USA uribe.convers@gmail.com.
authors.forename: Simon
authors.initials: S
authors.lastname: Uribe-Convers
authors.affiliation: Department of Biological Sciences, University of Idaho, 875 Perimeter MS 3051, Moscow, Idaho 83844-3051, USA.
authors.forename: David C
authors.initials: DC
authors.lastname: Tank
mesh_terms: D001483:Base Sequence; D005075:Biological Evolution; D018744:DNA, Plant / Q000737:chemistry / Q000235:genetics; D005060:Europe; D008969:Molecular Sequence Data; D031670:Orobanchaceae / Q000235:genetics*; D010802:Phylogeny; D058974:Phylogeography; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013020:South America
chemical_list: D018744:DNA, Plant
keywords: Bartsia; Bellardia; Neobartsia; Orobanchaceae; Páramo; Rhinantheae; dispersification