title: Absence of phylogenetic signal in the niche structure of meadow plant communities.
abstract: A significant proportion of the global diversity of flowering plants has evolved in recent geological time, probably through adaptive radiation into new niches. However, rapid evolution is at odds with recent research which has suggested that plant ecological traits, including the beta- (or habitat) niche, evolve only slowly. We have quantified traits that determine within-habitat alpha diversity (alpha niches) in two communities in which species segregate on hydrological gradients. Molecular phylogenetic analysis of these data shows practically no evidence of a correlation between the ecological and evolutionary distances separating species, indicating that hydrological alpha niches are evolutionarily labile. We propose that contrasting patterns of evolutionary conservatism for alpha- and beta-niches is a general phenomenon necessitated by the hierarchical filtering of species during community assembly. This determines that species must have similar beta niches in order to occupy the same habitat, but different alpha niches in order to coexist.
authors.affiliation: Department of Biological Sciences, The Open University, Walton Hall, Milton Keynes MK7 6AA, UK. j.silvertown@open.ac.uk
authors.forename: Jonathan
authors.initials: J
authors.lastname: Silvertown
authors.forename: Kevin
authors.initials: K
authors.lastname: McConway
authors.forename: David
authors.initials: D
authors.lastname: Gowing
authors.forename: Mike
authors.initials: M
authors.lastname: Dodd
authors.forename: Michael F
authors.initials: MF
authors.lastname: Fay
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Joseph
authors.forename: Konrad
authors.initials: K
authors.lastname: Dolphin
mesh_terms: D001483:Base Sequence; D044822:Biodiversity; D004739:England; D008954:Models, Biological; D008969:Molecular Sequence Data; D010802:Phylogeny; D010944:Plants / Q000145:classification / Q000235:genetics*