title: Conservatism of ecological niches in evolutionary time
abstract: Theory predicts low niche differentiation between species over evolutionary time scales, but little empirical evidence is available. Reciprocal geographic predictions based on ecological niche models of sister taxon pairs of birds, mammals, and butterflies in southern Mexico indicate niche conservatism over several million years of independent evolution (between putative sister taxon pairs) but little conservatism at the level of families. Niche conservatism over such time scales indicates that speciation takes place in geographic, not ecological, dimensions and that ecological differences evolve later.
authors.affiliation: Natural History Museum, The University of Kansas, Lawrence, KS 66045, USA. Instituto de Ecologia, Universidad Nacional Autonoma de Mexico, Mexico, D.F. 04510, Mexico. Departamento de Zoologia, Instituto de Biologia, Universidad Nacional A.
authors.initials: AT
authors.lastname: Peterson
authors.lastname: Sober n J
authors.initials: V
authors.lastname: Sanchez-Cordero