Kinziger Andrew P, Hellmair Michael, McCraney W Tyler, Jacobs David K, Goldsmith Greg
Department of Fisheries Biology, Humboldt State University, One Harpst Street, Arcata, CA, 95521, USA.
Landesfischereizentrum Vorarlberg, Auhafendamm 1, 6971, Hard, Austria.
Mol Ecol. 2015 Nov;24(22):5544-60. doi: 10.1111/mec.13424. Epub 2015 Nov 6.
Extinction and colonization dynamics are critical to understanding the evolution and conservation of metapopulations. However, traditional field studies of extinction-colonization are potentially fraught with detection bias and have rarely been validated. Here, we provide a comparison of molecular and field-based approaches for assessment of the extinction-colonization dynamics of tidewater goby (Eucyclogobius newberryi) in northern California. Our analysis of temporal genetic variation across 14 northern California tidewater goby populations failed to recover genetic change expected with extinction-colonization cycles. Similarly, analysis of site occupancy data from field studies (94 sites) indicated that extinction and colonization are very infrequent for our study populations. Comparison of the approaches indicated field data were subject to imperfect detection, and falsely implied extinction-colonization cycles in several instances. For northern California populations of tidewater goby, we interpret the strong genetic differentiation between populations and high degree of within-site temporal stability as consistent with a model of drift in the absence of migration, at least over the past 20-30 years. Our findings show that tidewater goby exhibit different population structures across their geographic range (extinction-colonization dynamics in the south vs. drift in isolation in the north). For northern populations, natural dispersal is too infrequent to be considered a viable approach for recolonizing extirpated populations, suggesting that species recovery will likely depend on artificial translocation in this region. More broadly, this work illustrates that temporal genetic analysis can be used in combination with field data to strengthen inference of extinction-colonization dynamics or as a stand-alone tool when field data are lacking.
灭绝和定殖动态对于理解集合种群的演化和保护至关重要。然而，传统的灭绝 - 定殖实地研究可能存在检测偏差，并且很少得到验证。在此，我们比较了基于分子和实地的方法，以评估加利福尼亚北部潮汐虾虎鱼（Eucyclogobius newberryi）的灭绝 - 定殖动态。我们对加利福尼亚北部14个潮汐虾虎鱼种群的时间遗传变异分析未能发现灭绝 - 定殖循环预期的遗传变化。同样，对实地研究（94个地点）的位点占用数据的分析表明，我们研究的种群中灭绝和定殖非常罕见。方法比较表明，实地数据存在检测不完美的问题，并且在几个实例中错误地暗示了灭绝 - 定殖循环。对于加利福尼亚北部的潮汐虾虎鱼种群，我们将种群间强烈的遗传分化和位点内高度的时间稳定性解释为与至少在过去20 - 30年中不存在迁移情况下的漂变模型一致。我们的研究结果表明，潮汐虾虎鱼在其地理范围内呈现出不同的种群结构（南部为灭绝 - 定殖动态，北部为孤立漂变）。对于北部种群，自然扩散过于罕见以至于不能被视为重新定殖灭绝种群的可行方法，这表明该地区的物种恢复可能依赖于人工迁移。更广泛地说，这项工作表明时间遗传分析可以与实地数据结合使用，以加强对灭绝 - 定殖动态的推断，或者在缺乏实地数据时作为独立工具使用。
