title: Integrating phylogeography and species distribution models: cryptic distributional responses to past climate change in an endemic rodent from the central Chile hotspot.
abstract: OBJECTIVE
  Biodiversity losses under the species level may have been severely underestimated in future global climate change scenarios. Therefore, it is important to characterize the diversity units at this level, as well as to understand their ecological responses to climatic forcings. We have chosen an endemic rodent from a highly endangered ecogeographic area as a model to look for distributional responses below the species level:Phyllotis darwini.
  
  
  METHODS
  The central Chile biodiversity hotspot: This area harbours a high number of endemic species, and it is known to have experienced vegetational displacements between two mountain systems during and after the Last Glacial Maximum.
  
  
  METHODS
  We have characterized cryptic lineages insideP. darwiniin a classic phylogeographic approach; those intraspecific lineages were considered as relevant units to construct distribution models at Last Glacial Maximum and at present, as border climatic conditions. Differences in distribution between border conditions for each lineage were interpreted as distributional responses to post-glacial climate change.
  
  
  RESULTS
  The species is composed of two major phylogroups: one of them has a broad distribution mainly across the valley but also in mountain ranges, whereas the other displays a disjunct distribution across both mountain ranges and always above 1500 m. The lineage distribution model under LGM climatic conditions suggests that both lineages were co-distributed in the southern portion ofP. darwini'scurrent geographic range, mainly at the valley and at the coast.
  
  
  CONCLUSIONS
  Present distribution of lineages inP. darwiniis the consequence of a cryptic distributional response to climate change after LGM: postglacial northward colonization, with strict altitudinal segregation of both phylogroups.
authors.affiliation: Laboratorio de Biología Evolutiva, Departamento de Ecología, Pontificia Universidad Católica de Chile, Casilla 114-D, Santiago 6513677, Chile.
authors.forename: Pablo
authors.initials: P
authors.lastname: Gutiérrez-Tapia
authors.affiliation: Laboratorio de Biología Evolutiva, Departamento de Ecología, Pontificia Universidad Católica de Chile, Casilla 114-D, Santiago 6513677, Chile.
authors.forename: R Eduardo
authors.initials: RE
authors.lastname: Palma
keywords: Biodiversity hotspots; Last Glacial Maximum; Phyllotis darwini; central Chile; cryptic diversity; distribution models; past climate change; phylogeography