title: Climatic drivers of hemispheric asymmetry in global patterns of ant species richness.
abstract: Although many taxa show a latitudinal gradient in richness, the relationship between latitude and species richness is often asymmetrical between the northern and southern hemispheres. Here we examine the latitudinal pattern of species richness across 1003 local ant assemblages. We find latitudinal asymmetry, with southern hemisphere sites being more diverse than northern hemisphere sites. Most of this asymmetry could be explained statistically by differences in contemporary climate. Local ant species richness was positively associated with temperature, but negatively (although weakly) associated with temperature range and precipitation. After contemporary climate was accounted for, a modest difference in diversity between hemispheres persisted, suggesting that factors other than contemporary climate contributed to the hemispherical asymmetry. The most parsimonious explanation for this remaining asymmetry is that greater climate change since the Eocene in the northern than in the southern hemisphere has led to more extinctions in the northern hemisphere with consequent effects on local ant species richness.
authors.affiliation: Department of Biology, North Carolina State University, Raleigh, NC 27695, USA. rob_dunn@ncsu.edu
authors.forename: Robert R
authors.initials: RR
authors.lastname: Dunn
authors.forename: Donat
authors.initials: D
authors.lastname: Agosti
authors.forename: Alan N
authors.initials: AN
authors.lastname: Andersen
authors.forename: Xavier
authors.initials: X
authors.lastname: Arnan
authors.forename: Carsten A
authors.initials: CA
authors.lastname: Bruhl
authors.forename: Xim
authors.initials: X
authors.lastname: Cerdá
authors.forename: Aaron M
authors.initials: AM
authors.lastname: Ellison
authors.forename: Brian L
authors.initials: BL
authors.lastname: Fisher
authors.forename: Matthew C
authors.initials: MC
authors.lastname: Fitzpatrick
authors.forename: Heloise
authors.initials: H
authors.lastname: Gibb
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Gotelli
authors.forename: Aaron D
authors.initials: AD
authors.lastname: Gove
authors.forename: Benoit
authors.initials: B
authors.lastname: Guenard
authors.forename: Milan
authors.initials: M
authors.lastname: Janda
authors.forename: Michael
authors.initials: M
authors.lastname: Kaspari
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Laurent
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Lessard
authors.forename: John T
authors.initials: JT
authors.lastname: Longino
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Majer
authors.forename: Sean B
authors.initials: SB
authors.lastname: Menke
authors.forename: Terrence P
authors.initials: TP
authors.lastname: McGlynn
authors.forename: Catherine L
authors.initials: CL
authors.lastname: Parr
authors.forename: Stacy M
authors.initials: SM
authors.lastname: Philpott
authors.forename: Martin
authors.initials: M
authors.lastname: Pfeiffer
authors.forename: Javier
authors.initials: J
authors.lastname: Retana
authors.forename: Andrew V
authors.initials: AV
authors.lastname: Suarez
authors.forename: Heraldo L
authors.initials: HL
authors.lastname: Vasconcelos
authors.forename: Michael D
authors.initials: MD
authors.lastname: Weiser
authors.forename: Nathan J
authors.initials: NJ
authors.lastname: Sanders
mesh_terms: D000818:Animals; D001000:Ants / Q000235:genetics / Q000502:physiology*; D044822:Biodiversity; D005075:Biological Evolution; D002980:Climate