Can novel genetic analyses help to identify low-dispersal marine invasive species?
Article first published online: 24 JUN 2014
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Ecology and Evolution
Volume 4, Issue 14, pages 2848–2866, July 2014
How to Cite
Ecology and Evolution 2014; 4(14):2848–2866
- Issue published online: 21 JUL 2014
- Article first published online: 24 JUN 2014
- Manuscript Accepted: 6 MAY 2014
- Manuscript Revised: 4 MAY 2014
- Manuscript Received: 19 APR 2014
- Australian Research Council. Grant Number: DP110101275
- biological invasion;
- coalescent theory;
- founder effect;
- genetic bottleneck;
- sea squirt
Genetic methods can be a powerful tool to resolve the native versus introduced status of populations whose taxonomy and biogeography are poorly understood. The genetic study of introduced species is presently dominated by analyses that identify signatures of recent colonization by means of summary statistics. Unfortunately, such approaches cannot be used in low-dispersal species, in which recently established populations originating from elsewhere in the species' native range also experience periods of low population size because they are founded by few individuals. We tested whether coalescent-based molecular analyses that provide detailed information about demographic history supported the hypothesis that a sea squirt whose distribution is centered on Tasmania was recently introduced to mainland Australia and New Zealand through human activities. Methods comparing trends in population size (Bayesian Skyline Plots and Approximate Bayesian Computation) were no more informative than summary statistics, likely because of recent intra-Tasmanian dispersal. However, IMa2 estimates of divergence between putatively native and introduced populations provided information at a temporal scale suitable to differentiate between recent (potentially anthropogenic) introductions and ancient divergence, and indicated that all three non-Tasmanian populations were founded during the period of European settlement. While this approach can be affected by inaccurate molecular dating, it has considerable (albeit largely unexplored) potential to corroborate nongenetic information in species with limited dispersal capabilities.