The evolution of antipredator behaviour following relaxed and reversed selection in Alaskan threespine stickleback fish.
The evolution of antipredator behaviour following relaxed and reversed selection in Alaskan threespine stickleback fish.
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DOI：
10.1016/j.anbehav.2015.05.009
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发表时间：
2015-08-01
期刊：
影响因子：
2.5
通讯作者：
Foster SA
中科院分区：
文献类型：
--
作者：
Wund MA;Baker JA;Golub JL;Foster SA
改变环境，无论是通过自然还是人为原因，都可能导致某些选择压力的丧失（“放松选择”），甚至可能恢复许多代都没有遇到的选择剂（“反向选择”）。我们研究了三棘鱼Gasterostues aculeatus L.在适应性辐射中放松选择和反向选择的结果，孤立的种群会遇到各种各样的捕食机制。海洋棘鱼，代表了淡水辐射的祖先，遇到了许多食鱼的鱼类。另一方面，衍生的淡水种群随着捕食者的存在而变化。一些种群遇到本地鲑鱼，而另一些种群在数千代中没有经历过大型鱼类的捕食（放松选择种群）。在过去的几十年里，一些放松选择的种群已经有了运动鱼类，包括虹鳟鱼，虹鳟鱼（Oncorhynchus mykiss）（反向选择）。我们研究的行为反应，刺鱼从三个种群的每一种类型的模拟攻击鳟鱼和鸟类，以确定是否放松和反向选择导致分歧的行为，以及这种分歧是否是捕食者的具体。无鳟鱼种群的鱼表现出较弱的鳟鱼的反应，预测，但这些反应是类似的海洋（祖先）人口。与鳟鱼，无论是本地或引进，共发生的人群中的鱼，表现出升高的抗捕食者的反应，表明在淡水中，鳟鱼捕食选择增强抗捕食者的反应，这可以非常迅速地演变。实验室饲养和野生捕获的个人的比较表明，这种变化的学习和遗传成分的组合。模型鸟天桥的反应弱联系到捕食环境，这表明鳟鱼捕食的损失可能会部分影响对鸟类的反应的演变。我们的研究结果拒绝了这一假设，即捕食性鸟类的持续存在已足以维持对食鱼鱼类在放松选择期间的反应。
Changing environments, whether through natural or anthropogenic causes, can lead to the loss of some selective pressures (‘relaxed selection’) and possibly even the reinstatement of selective agents not encountered for many generations (‘reversed selection’). We examined the outcome of relaxed and reversed selection in the adaptive radiation of the threespine stickleback fish, Gasterostues aculeatus L., in which isolated populations encounter a variety of predation regimes. Oceanic stickleback, which represent the ancestral founders of the freshwater radiation, encounter many piscivorous fish. Derived, freshwater populations, on the other hand, vary with respect to the presence of predators. Some populations encounter native salmonids, whereas others have not experienced predation by large fish in thousands of generations (relax-selected populations). Some relax-selected populations have had sport fish, including rainbow trout, Oncorhynchus mykiss, introduced within the past several decades (reverse-selected). We examined the behavioural responses of stickleback from three populations of each type to simulated attacks by trout and birds to determine whether relaxed and reversed selection has led to divergence in behaviour, and whether this divergence was predator specific. Fish from trout-free populations showed weak responses to trout, as predicted, but these responses were similar to those of oceanic (ancestral) populations. Fish from populations that co-occur with trout, whether native or introduced, showed elevated antipredator responses, indicating that in freshwater, trout predation selects for enhanced antipredator responses, which can evolve extremely rapidly. Comparison of laboratory-reared and wild-caught individuals suggests a combination of learned and genetic components to this variation. Responses to a model bird flyover were weakly linked to predation environment, indicating that the loss of predation by trout may partially influence the evolution of responses to birds. Our results reject the hypothesis that the consistent presence of predatory birds has been sufficient to maintain responses to piscivorous fish under periods of relaxed selection.