title: The biodiversity hotspot as evolutionary hot-bed: spectacular radiation of Erica in the Cape Floristic Region.
abstract: The disproportionate species richness of the world's biodiversity hotspots could be explained by low extinction (the evolutionary "museum") and/or high speciation (the "hot-bed") models. We test these models using the largest of the species rich plant groups that characterise the botanically diverse Cape Floristic Region (CFR): the genus Erica L. We generate a novel phylogenetic hypothesis informed by nuclear and plastid DNA sequences of c. 60 % of the c. 800 Erica species (of which 690 are endemic to the CFR), and use this to estimate clade ages (using RELTIME; BEAST), net diversification rates (GEIGER), and shifts in rates of diversification in different areas (BAMM; MuSSE).
  
  
  
  The diversity of Erica species in the CFR is the result of a single radiation within the last c. 15 million years. Compared to ancestral lineages in the Palearctic, the rate of speciation accelerated across Africa and Madagascar, with a further burst of speciation within the CFR that also exceeds the net diversification rates of other Cape clades.
  
  
  
  Erica exemplifies the "hotbed" model of assemblage through recent speciation, implying that with the advent of the modern Cape a multitude of new niches opened and were successively occupied through local species diversification.
authors.affiliation: Department of Biochemistry, University of Stellenbosch, Private Bag X1, Matieland, 7602, South Africa. pirie@uni-mainz.de.|Institut für Spezielle Botanik und Botanischer Garten, Johannes Gutenberg-Universität, Anselm-Franz-von-Bentzelweg 9a, 55099, Mainz, Germany. pirie@uni-mainz.de.
authors.forename: M D
authors.initials: MD
authors.lastname: Pirie
authors.affiliation: Department of Botany and Zoology, University of Stellenbosch, Private Bag X1, Matieland, 7602, South Africa.
authors.forename: E G H
authors.initials: EG
authors.lastname: Oliver
authors.affiliation: INRES Pflanzenzüchtung, Rheinische Friedrich-Wilhelms-Universität Bonn, Katzenburgweg 5, 53115, Bonn, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Mugrabi de Kuppler
authors.affiliation: Institut für Spezielle Botanik und Botanischer Garten, Johannes Gutenberg-Universität, Anselm-Franz-von-Bentzelweg 9a, 55099, Mainz, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Gehrke
authors.affiliation: Department of Biochemistry, University of Stellenbosch, Private Bag X1, Matieland, 7602, South Africa.
authors.forename: N C
authors.initials: NC
authors.lastname: Le Maitre
authors.affiliation: Institut für Spezielle Botanik und Botanischer Garten, Johannes Gutenberg-Universität, Anselm-Franz-von-Bentzelweg 9a, 55099, Mainz, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Kandziora
authors.affiliation: Department of Biochemistry, University of Stellenbosch, Private Bag X1, Matieland, 7602, South Africa.
authors.forename: D U
authors.initials: DU
authors.lastname: Bellstedt
mesh_terms: D044822:Biodiversity; D005075:Biological Evolution; D029791:Ericaceae / Q000145:classification / Q000235:genetics*; D049810:Genetic Speciation; D010802:Phylogeny; D013019:South Africa
keywords: Biodiversity; Cape Floristic Region; Diversification; Erica; Evolution