title: Why does diversification slow down?
abstract: Studies of phylogenetic diversification often show evidence for slowdowns in diversification rates over the history of clades. Recent studies seeking biological explanations for this pattern have emphasized the role of niche differentiation, as in hypotheses of adaptive radiation and ecological limits to diversity. Yet many other biological explanations might underlie diversification slowdowns. In this paper, we focus on the geographic context of diversification, environment-driven bursts of speciation, failure of clades to keep pace with a changing environment, and protracted speciation. We argue that, despite being currently underemphasized, these alternatives represent biologically plausible explanations that should be considered along with niche differentiation. Testing the importance of these alternative hypotheses might yield fundamentally different explanations for what influences species richness within clades through time.
authors.affiliation: Center for Applied Mathematics, École Polytechnique, UMR 7641 CNRS, Route de Saclay, 91128 Palaiseau Cedex, France. Electronic address: moen@biologie.ens.fr.
authors.forename: Daniel
authors.initials: D
authors.lastname: Moen
authors.affiliation: Center for Applied Mathematics, École Polytechnique, UMR 7641 CNRS, Route de Saclay, 91128 Palaiseau Cedex, France.
authors.forename: Hélène
authors.initials: H
authors.lastname: Morlon
mesh_terms: D044822:Biodiversity; D005075:Biological Evolution; D017753:Ecosystem; D053476:Extinction, Biological; D049810:Genetic Speciation; D010802:Phylogeny; D058974:Phylogeography
keywords: adaptive radiation; biogeography; diversification; ecological limits; extinction; speciation; wax–wane dynamics