title: Correlates of species richness in mammals: body size, life history, and ecology.
abstract: We present the most extensive examination to date of proposed correlates of species richness. We use rigorous phylogenetic comparative techniques, data for 1,692 mammal species in four clades, and multivariate statistics to test four hypotheses about species richness and compare the evidence for each. Overall, we find strong support for the life-history model of diversification. Species richness is significantly correlated with shorter gestation period in the carnivores and large litter size in marsupials. These traits and short interbirth intervals are also associated with species richness in a pooled analysis of all four clades. Additionally, we find some support for the abundance hypotheses in different clades of mammals: abundance correlates positively with species richness in primates but negatively in microchiropterans. Our analyses provide no evidence that mammalian species richness is associated with body size or degree of sexual dimorphism.
authors.affiliation: Division of Biology, Imperial College, Silwood Park, Ascot, Berkshire SL5 7PY, United Kingdom. nick.isaac@ioz.ac.uk
authors.forename: Nick J B
authors.initials: NJ
authors.lastname: Isaac
authors.forename: Kate E
authors.initials: KE
authors.lastname: Jones
authors.forename: John L
authors.initials: JL
authors.lastname: Gittleman
authors.forename: Andy
authors.initials: A
authors.lastname: Purvis
mesh_terms: D000818:Animals; D044822:Biodiversity; D049628:Body Size; D049810:Genetic Speciation; D008098:Litter Size; D008322:Mammals / Q000033:anatomy & histology / Q000145:classification* / Q000235:genetics; D015999:Multivariate Analysis; D010802:Phylogeny; D012044:Regression Analysis; D012098:Reproduction / Q000502:physiology; D012727:Sex Characteristics