Title

Two pulses of diversification across the Isthmus of Tehuantepec in a montane Mexican bird fauna

Document Type

Article

Publication Date

9-2010

Publication Title

Proceedings of the Royal Soc. B

Publisher

Royal Society Publishing

Volume

277

First page number:

2675

Last page number:

2681

Abstract

Understanding the evolutionary history of the species in a particular region provides insights into how that fauna was formed. Of particular interest to biogeographers is examining the impact a geographical barrier had in generating temporal genetic diversity among codistributed species. We examined the impact a major New World barrier, the Isthmus of Tehuantepec (IT) in southern Mexico, had on a regional bird fauna. Specifically, genetic data from 10 montane-forest bird taxa were analysed using approximate Bayesian computation (ABC) to test the hypothesis of simultaneous intraspecific diversification at the IT. Because effective population size (Ne) has the greatest impact on coalescent times, thereby affecting tests of divergence among codistributed taxa, we chose priors for both current and ancestral Ne using empirical estimates of theta. The ABC method detected two discrete diversification events. Subsequent analysis with the number of diversification events constrained to two suggests that four taxa diverged in an older event, with the remaining six diverging more recently. Application of a range of mutation rates from 2.0 to 5.0% Myr-1 places both events within the Pleistocene or Late Pliocene, suggesting that fluctuations in montane habitat induced by climate cycles and a late Pliocene seaway may have fractured this montane bird fauna. The results presented here suggest this avian fauna responded in a relatively concerted fashion over the last several million years.

Keywords

Biodiversity; Biogeography; Phylogeography; Pleistocene; Population biology

Disciplines

Biodiversity | Ornithology | Population Biology

Language

English

Permissions

Use Find in Your Library, contact the author, or use interlibrary loan to garner a copy of the article. Publisher copyright policy allows author to archive post-print (author’s final manuscript). When post-print is available or publisher policy changes, the article will be deposited.

Identifier

DOI: http://ezproxy.library.unlv.edu/login?url=http://dx.doi.org/10.1098/rspb.2010.0343