Deep barriers, shallow divergences: reduced phylogeographical structure in the collared pika (Mammalia: Lagomorpha: Ochotona collaris)
Article first published online: 12 NOV 2012
© 2012 Blackwell Publishing Ltd
Journal of Biogeography
Volume 40, Issue 3, pages 466–478, March 2013
How to Cite
Lanier, H. C., Olson, L. E. (2013), Deep barriers, shallow divergences: reduced phylogeographical structure in the collared pika (Mammalia: Lagomorpha: Ochotona collaris). Journal of Biogeography, 40: 466–478. doi: 10.1111/jbi.12035
- Issue published online: 12 FEB 2013
- Article first published online: 12 NOV 2012
- Alaska Department of Fish and Game. Grant Numbers: EPS-0346770, DEB-0808619
- University of Alaska Museum. Grant Number: RR016466
- National Center for Research Resources. Grant Numbers: EPS-0346770, DEB-0808619, RR016466
- University of Alaska Ted McHenry Biology Field Research Fund
- American Society of Mammalogists
- Alaska Quaternary Center
- the Bruce Hayward Fund
- Alaska EPSCoR. Grant Number: EPS-0346770
- NSF. Grant Number: EPS-0346770
- National Science Foundation. Grant Numbers: EPS-0346770, DEB-0808619, RR016466
- collared pika;
- cytochrome b;
- niche modelling;
- Pleistocene climate change;
- population structure
Pikas (Ochotona spp.) are alpine specialists that show considerable morphological and genetic variation structured along latitudinal and elevational gradients. Recent studies of North American and Asian pikas have uncovered phylogeographical partitioning among separate mountain ranges and drainages, driven by Quaternary climate fluctuations. We tested the prediction that collared pikas (O. collaris) exhibit lower genetic diversity and less structure than other species of pika due to lower long-term habitat stability.
Eastern Beringia (Alaska and north-western Canada).
We examined phylogeographical variation in the collared pika (O. collaris) throughout much of its known range using the mitochondrial cytochrome b gene. Population divergence and genetic diversity were compared within and between mountain ranges. Genetic diversity was contrasted with current and Pleistocene habitat fragmentation inferred from ecological niche models.
Low but significant differentiation was evident between most populations of O. collaris, with little haplotype sharing among populations and a single phylogeographical break separating a genetically distinct haplogroup in the south-eastern part of its range. Variation was mostly structured within populations (as opposed to between populations or mountain ranges). When within-species nucleotide diversity in O. collaris, O. princeps and O. curzoniae was compared, genetic diversity was found to decline with increasing latitude.
Populations of O. collaris are less geographically structured and exhibit less variability than populations of either O. princeps or O. curzoniae. This pattern is better explained by the amount of available Pleistocene habitat predicted for each species than by current predicted habitat or population discontinuity. Collared pikas are currently considered to be a common species at low risk of extinction, but their habitat specificity, population subdivision, and low genetic variation may have consequences for their continued viability in a warming world.