Understanding the processes that cause speciation is a key aim of evolutionary biology. Lineages or biomes that exhibit recent and rapid diversification are ideal model systems for determining these processes. Species rich biomes reported to be of relatively recent origin, i.e., since the beginning of the Miocene, include Mediterranean ecosystems such as the California Floristic Province, oceanic islands such as the Hawaiian archipelago and the Neotropical high elevation ecosystem of the Páramos. Páramos constitute grasslands above the forest tree-line (at elevations of c. 2800–4700 m) with high species endemism. Organisms that occupy this ecosystem are a likely product of unique adaptations to an extreme environment that evolved during the last three to five million years when the Andes reached an altitude that was capable of sustaining this type of vegetation. We compared net diversification rates of lineages in fast evolving biomes using 73 dated molecular phylogenies. Based on our sample, we demonstrate that average net diversification rates of Páramo plant lineages are faster than those of other reportedly fast evolving hotspots and that the faster evolving lineages are more likely to be found in Páramos than the other hotspots. Páramos therefore represent the ideal model system for studying diversification processes. Most of the speciation events that we observed in the Páramos (144 out of 177) occurred during the Pleistocene possibly due to the effects of species range contraction and expansion that may have resulted from the well-documented climatic changes during that period. Understanding these effects will assist with efforts to determine how future climatic changes will impact plant populations.
Keywords: biodiversity hotspots, biogeography, evolutionary radiation, dated molecular phylogenies, net diversification rates, plant evolution, Páramos
Citation: Madriñán S, Cortés AJ and Richardson JE (2013) Páramo is the world's fastest evolving and coolest biodiversity hotspot. Front. Genet. 4:192. doi: 10.3389/fgene.2013.00192
Received: 28 May 2013; Accepted: 08 September 2013;
Published online: 09 October 2013.
Edited by:Federico Luebert, Freie Universität Berlin, Germany
Reviewed by:Christopher W. Dick, University of Michigan, USA
Copyright © 2013 Madriñán, Cortés and Richardson. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Santiago Madriñán, Laboratorio de Botánica y Sistemática, Universidad de los Andes, Apartado Aéreo 4976, Bogotá, DC 111711, Colombia e-mail: firstname.lastname@example.org