Title

Old Mice, Young Islands And Competing Biogeographical Hypotheses

Keywords

Biogeography; Demography; mtDNA; Peromyscus; Phylogenetics; Pleistocene

Abstract

Naturally occurring variation within a small rodent species native to the southeastern USA, Peromyscus polionotus, has interested biologists for nearly a century. This species has contributed significantly to our understanding of geographical variation and has often been presented as an example of adaptive evolution. Much of the interest in this organism has been predicated on assumptions that the species is relatively young (< 300 000 bp) and that coastal populations have a very recent history (< 10 000 bp). To test these assumptions and the prevailing biogeographical hypothesis (Recurrent Invasion), we examined nucleotide sequence data from the cytochrome b and D-loop mitochondrial regions (2449 bp) for 79 samples of P. polionotus collected across the Gulf Coast region of Florida and Alabama. Samples representing Peromyscus maniculatus bairdii, P. m. sonoriensis, P. m. pallescens, and P. keeni were used as outgroups. The degree of cytochrome b divergence (≈ 4.4%) between P. maniculatus and P. polionotus was higher than expected. Analyses consistently indicated that three distinct groups are represented within P. polionotus from the Gulf Coast region. Among these, coastal populations (beach mice) form a monophyletic group and apparently represent a substantially older group (≈ 200 000 year. separation) than previously recognized. Our results were counter to the core assumptions of the existing biogeographical model but were consistent with an alternative hypothesis (Shore-line Tracking) which provides a more parsimonious explanation for the observed patterns. This research provides new insight into the evolutionary history of P. polionotus and highlights the importance of considering biogeographical history when evaluating extant patterns of natural variation. © 2007 The Authors.

Publication Date

12-1-2007

Publication Title

Molecular Ecology

Volume

16

Issue

23

Number of Pages

5070-5083

Document Type

Article

Personal Identifier

scopus

DOI Link

https://doi.org/10.1111/j.1365-294X.2007.03582.x

Socpus ID

36348945342 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/36348945342

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