Research Beyond aridification: multiple explanations for the elevated diversification of cacti in the New World Succulent Biome Tania Hernandez-Hernandez1, Joseph W. Brown2, Boris O. Schlumpberger3, Luis E. Eguiarte4 and Susana Magallon 5 1Posgrado en Ciencias Biologicas, Instituto de Biologıa, Universidad Nacional Autonoma de Mexico, 3er Circuito de Ciudad Universitaria, Del. Coyoacan, Mexico D.F.04510, Mexico; 2Department of Ecology and Evolutionary Biology, University of Michigan, 830 North University Avenue, Ann Arbor, MI48109-1048, USA; 3Herrenhausen Gardens, Hannover, Germany; 4Departamento de Ecologıa Evolutiva, Instituto de Ecologıa, Universidad Nacional Autonoma de Mexico, 3er Circuito de Ciudad Universitaria, Del. Coyoacan, Mexico D.F. 04510, Mexico; 5Departamento de Botanica, Instituto de Biologıa, Universidad Nacional Autonoma de Mexico, 3er Circuito de Ciudad Universitaria, Del. Coyoacan, Mexico D.F. 04510, Mexico Summary Author for correspondence: Succulent plants are widely distributed, reaching their highest diversity in arid and semi-arid Susana Magallon regions. Their origin and diversification is thought to be associated with a global expansion of Tel: +52 55 5622 9087 aridity. We test this hypothesis by investigating the tempo and pattern of Cactaceae diversifi- Email:
[email protected] cation. Our results contribute to the understanding of the evolution of New World Succulent Received: 6 December 2013 Biomes. Accepted: 3 February 2014 We use the most taxonomically complete dataset currently available for Cactaceae. We estimate divergence times and utilize Bayesian and maximum likelihood methods that account New Phytologist (2014) for nonrandom taxonomic sampling, possible extinction scenarios and phylogenetic uncer- doi: 10.1111/nph.12752 tainty to analyze diversification rates, and evolution of growth form and pollination syn- drome.