title: Large punctuational contribution of speciation to evolutionary divergence at the molecular level.
abstract: A long-standing debate in evolutionary biology concerns whether species diverge gradually through time or by punctuational episodes at the time of speciation. We found that approximately 22% of substitutional changes at the DNA level can be attributed to punctuational evolution, and the remainder accumulates from background gradual divergence. Punctuational effects occur at more than twice the rate in plants and fungi than in animals, but the proportion of total divergence attributable to punctuational change does not vary among these groups. Punctuational changes cause departures from a clock-like tempo of evolution, suggesting that they should be accounted for in deriving dates from phylogenies. Punctuational episodes of evolution may play a larger role in promoting evolutionary divergence than has previously been appreciated.
authors.affiliation: School of Biological Sciences, University of Reading, Whiteknights, Reading RG6 6AJ, UK. m.pagel@rdg.ac.uk
authors.forename: Mark
authors.initials: M
authors.lastname: Pagel
authors.forename: Chris
authors.initials: C
authors.lastname: Venditti
authors.forename: Andrew
authors.initials: A
authors.lastname: Meade
mesh_terms: D000818:Animals; D001483:Base Sequence; D001499:Bayes Theorem; D004247:DNA / Q000235:genetics*; D004271:DNA, Fungal / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D019143:Evolution, Molecular; D018703:Founder Effect; D005658:Fungi / Q000145:classification / Q000235:genetics; D049810:Genetic Speciation; D014644:Genetic Variation; D016013:Likelihood Functions; D008433:Mathematics; D015233:Models, Statistical; D009154:Mutation; D010802:Phylogeny; D010944:Plants / Q000145:classification / Q000235:genetics; D016415:Sequence Alignment
chemical_list: D004271:DNA, Fungal; D018744:DNA, Plant; D004247:DNA