Evolution of juvenile growth rates in female guppies (Poecilia reticulata):: predator regime or resource level?
Evolution of juvenile growth rates in female guppies (Poecilia reticulata):: predator regime or resource level?
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DOI：
10.1098/rspb.2004.2899
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发表时间：
2005-02-07
影响因子：
4.7
通讯作者：
Reznick, DN
中科院分区：
文献类型：
--
作者：
Arendt, JD;Reznick, DN
最近的理论和实证研究认为，增长率可以演变和优化，而不是总是最大化。长期较低的资源可用性预计将有利于缓慢增长的演变，而获得死亡风险的规模庇护预计将有利于快速增长的演变。孔雀鱼（Poecilia reticulata）为了应对捕食而进化出行为、形态和生活史特征的差异，从而表明捕食者是选择的有效媒介。低捕食环境中的捕食者优先捕食小型孔雀鱼，但高捕食环境中的捕食者似乎没有选择性。由于孔雀鱼在低捕食环境中的生长速度可能超过其主要捕食者的生长速度，但不会在高捕食环境中生长，因此我们预测捕食行为会选择在低捕食环境中获得较高的生长率。然而，低捕食地区的生产力也往往低于高捕食地区，因此预测这些地区的孔雀鱼的生长速度应该较慢。在这里，我们比较了来自四个不同流域的高捕食性和低捕食性配对地点的第二代实验室出生的孔雀鱼的生长速度。在四分之二的比较中，来自高捕食地点的孔雀鱼的生长速度明显快于来自低捕食地点的孔雀鱼。我们还比较了来自野外引种试验地的实验室出生的后代，结果表明，引入低捕食环境的孔雀鱼在 13 年后进化出较慢的生长速度，尽管这仅在高食物水平下才明显。大量证据表明，在塑造增长率的演变方面，资源可用性比掠夺发挥着更重要的作用。
Recent theoretical and empirical work argues that growth rate can evolve and be optimized, rather than always being maximized. Chronically low resource availability is predicted to favour the evolution of slow growth, whereas attaining a size-refuge from mortality risk is predicted to favour the evolution of rapid growth. Guppies (Poecilia reticulata) evolve differences in behaviour, morphology and life-history traits in response to predation, thus demonstrating that predators are potent agents of selection. Predators in low-predation environments prey preferentially on small guppies, but those in high-predation environments appear to be non-selective. Because guppies can outgrow their main predator in low- but not high-predation localities, we predict that predation will select for higher growth rates in the low-predation environments. However, low-predation localities also tend to have lower productivity than high-predation localities, yielding the prediction that guppies from these sites should have slower growth rates. Here we compare the growth rates of the second laboratory-born generation of guppies from paired high- and low-predation localities from four different drainages. In, two out of four comparisons, guppies from high-predation sites grew significantly faster than their low-predation counterparts. We also compare laboratory born descendants from a field introduction experiment land show that guppies introduced to a low-predation environment evolved slower growth rates after 13 years, although this was evident only at the high food level. The weight of the evidence suggests that resource availability plays a more important role than predation in shaping the evolution of growth rates.