Comparative phylogeographic analyses illustrate the complex evolutionary history of threatened cloud forests of northern Mesoamerica

PLoS One. 2013;8(2):e56283. doi: 10.1371/journal.pone.0056283. Epub 2013 Feb 7.

Abstract

Comparative phylogeography can elucidate the influence of historical events on current patterns of biodiversity and can identify patterns of co-vicariance among unrelated taxa that span the same geographic areas. Here we analyze temporal and spatial divergence patterns of cloud forest plant and animal species and relate them to the evolutionary history of naturally fragmented cloud forests--among the most threatened vegetation types in northern Mesoamerica. We used comparative phylogeographic analyses to identify patterns of co-vicariance in taxa that share geographic ranges across cloud forest habitats and to elucidate the influence of historical events on current patterns of biodiversity. We document temporal and spatial genetic divergence of 15 species (including seed plants, birds and rodents), and relate them to the evolutionary history of the naturally fragmented cloud forests. We used fossil-calibrated genealogies, coalescent-based divergence time inference, and estimates of gene flow to assess the permeability of putative barriers to gene flow. We also used the hierarchical Approximate Bayesian Computation (HABC) method implemented in the program msBayes to test simultaneous versus non-simultaneous divergence of the cloud forest lineages. Our results show shared phylogeographic breaks that correspond to the Isthmus of Tehuantepec, Los Tuxtlas, and the Chiapas Central Depression, with the Isthmus representing the most frequently shared break among taxa. However, dating analyses suggest that the phylogeographic breaks corresponding to the Isthmus occurred at different times in different taxa. Current divergence patterns are therefore consistent with the hypothesis of broad vicariance across the Isthmus of Tehuantepec derived from different mechanisms operating at different times. This study, coupled with existing data on divergence cloud forest species, indicates that the evolutionary history of contemporary cloud forest lineages is complex and often lineage-specific, and thus difficult to capture in a simple conservation strategy.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Americas
  • Animals
  • Endangered Species / statistics & numerical data*
  • Evolution, Molecular*
  • Gene Flow
  • Genetic Variation
  • Phylogeography
  • Plants / classification
  • Plants / genetics
  • Sequence Analysis, DNA
  • Spatio-Temporal Analysis
  • Trees / classification
  • Trees / genetics*

Grants and funding

This work was supported by the Consejo Nacional de Ciencia y Tecnología (CONACyT, http://www.conacyt.gob.mx) under agreement no. 61710 for the project Filogeografía y genética de poblaciones del bosque mesófilo de montaña: refugios, dispersión y divergencia en un archipiélago directed by Juan Francisco Ornelas. Additional research funds were provided by research grants from CONACyT to C.G.R. (25888) and C.G. (49062), the International Foundation for Science to C.G.R. and J.F.O (D/4050-1), the Departamento de Biología Evolutiva, Instituto de Ecología to J.F.O. (902-12-563), and by the Dirección General of the Instituto de Ecología, AC to V.S. A postdoctoral fellowship (61710) and a doctoral scholarship (203259) from CONACyT were granted to E.R.S. and C.G., respectively. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.