Phylogeographical analysis of mtDNA data indicates postglacial expansion from multiple glacial refugia in woodland caribou (Rangifer tarandus caribou)

PLoS One. 2012;7(12):e52661. doi: 10.1371/journal.pone.0052661. Epub 2012 Dec 21.

Abstract

Glacial refugia considerably shaped the phylogeographical structure of species and may influence intra-specific morphological, genetic, and adaptive differentiation. However, the impact of the Quaternary ice ages on the phylogeographical structure of North American temperate mammalian species is not well-studied. Here, we surveyed ~1600 individuals of the widely distributed woodland caribou (Rangifer tarandus caribou) using mtDNA control region sequences to investigate if glacial refugia contributed to the phylogeographical structure in this subspecies. Phylogenetic tree reconstruction, a median-joining network, and mismatch distributions supported postglacial expansions of woodland caribou from three glacial refugia dating back to 13544-22005 years. These three lineages consisted almost exclusively of woodland caribou mtDNA haplotypes, indicating that phylogeographical structure was mainly shaped by postglacial expansions. The putative centres of these lineages are geographically separated; indicating disconnected glacial refugia in the Rocky Mountains, east of the Mississippi, and the Appalachian Mountains. This is in congruence with the fossil record that caribou were distributed in these areas during the Pleistocene. Our results suggest that the last glacial maximum substantially shaped the phylogeographical structure of this large mammalian North American species that will be affected by climatic change. Therefore, the presented results will be essential for future conservation planning in woodland caribou.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Canada
  • DNA, Mitochondrial*
  • Evolution, Molecular
  • Haplotypes
  • Phylogeny
  • Phylogeography
  • Population Dynamics
  • Reindeer / classification
  • Reindeer / genetics*

Substances

  • DNA, Mitochondrial

Grant support

Funding for this study was provided by NSERC through the Collaborative, Strategic and Discovery Programs. Additional funding and in-kind support was provided by Parks Canada, Manitoba Conservation, Manitoba Hydro, Prince Albert Model Forest, Saskatchewan Environment, Ontario Ministry of Natural Resources, and the Species at Risk Recovery Fund. The funders contributed to the field work but had no role in study design, lab and data analysis, decision to publish, or preparation of the manuscript.