Journal article
Landscape genetics of the Tasmanian devil: implications for spread of an infectious cancer
Conservation genetics, Vol.18(6), pp.1287-1297
12/2017
Handle:
https://hdl.handle.net/2376/116190
Abstract
Emerging infectious diseases are increasingly recognized in species’ declines and extinctions. Landscape genetics can be used as a tool to predict disease emergence and spread. The Tasmanian devil is threatened with extinction by a nearly 100% fatal transmissible cancer, which has spread across 95% of the species’ geographic range in 20 years. Here, we present a landscape genetic analysis in the last remaining uninfected parts of the Tasmanian devil’s geographic range to: describe population genetic structure, characterize genetic diversity, and test the influence of landscape variables on Tasmanian devil gene flow to assess the potential for disease spread. In contrast to previous genetic studies on Tasmanian devils showing evidence for two genetic populations island-wide, our genetic based assignment tests and spatial principal components analyses suggest at least two, and possibly three, populations in a study area that is approximately 15% of the size of the overall species’ geographic range. Positive spatial autocorrelation declined at about 40 km, in contrast to 80 km in eastern populations, highlighting the need for range-wide genetic studies. Strong genetic structure was found between devils in the northern part of the study area and those found south of Macquarie Harbor, with weaker structure found between the northeastern and northwestern portion of our study area. Consistent with previous work, we found low overall genetic diversity, likely owing to a combination of founder effects and extreme weather events thousands of years ago that likely caused large-scale population declines. We also found possible signs of recent bottlenecks, perhaps resulting from forest clearing for dairy farming in the central part of the study area. This human disturbance also may have contributed to weak genetic structuring detected between the northeastern and northwestern part of the study area. Individual-based least cost path modeling showed limited influence of landscape variables on gene flow, with weak effects of variation in elevation in the northeast. In the northwest, however, landscape genetic models did not perform better than the null isolation-by-distance model. At the larger spatial scale of the northern part of the study area, elevation and temperatures were negatively correlated with gene flow, consistent with low dispersal suitability of higher elevation habitats that have lower temperatures and dense, wet vegetation. Overall, Tasmanian devils are a highly vagile species for which dispersal and gene flow appear to be influenced little by landscape features, and spread of devil facial tumor disease to the remaining portion of the devil’s geographic range seems imminent. Nonetheless, strong genetic structure found between the northern and southern portions of our study area, combined with low densities and limited possible colonization of DFTD from the east suggest there is some time for implementation of management strategies.
Metrics
28 Record Views
Details
- Title
- Landscape genetics of the Tasmanian devil: implications for spread of an infectious cancer
- Creators
- Andrew Storfer - School of Biological Sciences Washington State University Pullman WA 99164-5236 USABrendan Epstein - School of Biological Sciences Washington State University Pullman WA 99164-5236 USAMenna Jones - School of Biological Sciences University of Tasmania Private Bag 55 Hobart TAS 7001 AustraliaSteven Micheletti - School of Biological Sciences Washington State University Pullman WA 99164-5236 USAStephen Spear - The Wilds 14000 International Road Cumberland OH 43732 USAShelly Lachish - Unit of Health Care Epidemiology, Department of Population Health University of Oxford Oxford UKSamantha Fox - Department of Primary Industries, Parks, Water and Environment GPO Box 44 Hobart TAS 7001 Australia
- Publication Details
- Conservation genetics, Vol.18(6), pp.1287-1297
- Academic Unit
- Biological Sciences, School of
- Publisher
- Springer Netherlands; Dordrecht
- Grant note
- DEB-1316549 / Directorate for Biological Sciences (http://dx.doi.org/10.13039/100000076) FT100100250 / Australian Research Council (http://dx.doi.org/10.13039/501100000923)
- Identifiers
- 99900548195401842
- Language
- English
- Resource Type
- Journal article