Document Type

Article

Publication Date

5-2011

Publication Title

BMC Evolutionary Biology

Publisher

BioMed Central

Volume

11

First page number:

136

Abstract

Background

Earth history events such as climate change are believed to have played a major role in shaping patterns of genetic structure and diversity in species. However, there is a lag between the time of historical events and the collection of present-day samples that are used to infer contemporary population structure. During this lag phase contemporary processes such as dispersal or non-random mating can erase or reinforce population differences generated by historical events. In this study we evaluate the role of both historical and contemporary processes on the phylogeography of a widespread North American songbird, the Northern Cardinal, Cardinalis cardinalis.

Results

Phylogenetic analysis revealed deep mtDNA structure with six lineages across the species' range. Ecological niche models supported the same geographic breaks revealed by the mtDNA. A paleoecological niche model for the Last Glacial Maximum indicated that cardinals underwent a dramatic range reduction in eastern North America, whereas their ranges were more stable in México. In eastern North America cardinals expanded out of glacial refugia, but we found no signature of decreased genetic diversity in areas colonized after the Last Glacial Maximum. Present-day demographic data suggested that population growth across the expansion cline is positively correlated with latitude. We propose that there was no loss of genetic diversity in areas colonized after the Last Glacial Maximum because recent high-levels of gene flow across the region have homogenized genetic diversity in eastern North America.

Conclusion

We show that both deep historical events as well as demographic processes that occurred following these events are critical in shaping genetic pattern and diversity in C. cardinalis. The general implication of our results is that patterns of genetic diversity are best understood when information on species history, ecology, and demography are considered simultaneously.

Keywords

Cardinalis cardinalis; Northern Cardinal; Phylogeography; Population biology; Population genetics

Disciplines

Molecular Genetics | Ornithology | Population Biology

Language

English

Permissions

This is an Open Access article distributed under the terms of the Creative Commons Attribution License. The electronic version of this article is the complete one and can be found online at: http://www.biomedcentral.com/1471-2148/11/136.

Identifier

DOI: http://ezproxy.library.unlv.edu/login?url=http://dx.doi.org/10.1186/1471-2148-11-136