A TEST OF ECOLOGICALLY DEPENDENT POSTMATING ISOLATION BETWEEN SYMPATRIC STICKLEBACKS
A TEST OF ECOLOGICALLY DEPENDENT POSTMATING ISOLATION BETWEEN SYMPATRIC STICKLEBACKS
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同域刺鱼之间生态依赖的交配后隔离试验
DOI：
10.1111/j.0014-3820.2002.tb01342.x
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发表时间：
2002
期刊：
影响因子：
--
通讯作者：
H. Rundle
中科院分区：
文献类型：
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作者：
H. Rundle
摘要生态物种形成是由于居住在不同环境或开发替代资源的种群之间的不同自然选择而最终导致生殖隔离的结果。我测试了一个预测的生态模型，关于两个年轻的，同域物种的threespine刺鱼（底栖动物和湖沼动物）之间的杂种的健身。这两个物种在生态和形态上是不同的：底栖动物适应于在湖泊的沿岸的区以无脊椎动物为食，而湖沼动物则适应于在开阔水域以浮游动物为食。两种类型的混合动力车，底栖回交和湖沼回交，以及两个亲本物种的生长速度进行了评估，在两个父母的栖息地在湖泊中的外壳。回交的使用是理想的，因为它们在两个栖息地的增长率的比较估计其健身的生态依赖的组成部分，同时控制任何内在的遗传不相容性，可能存在于底栖动物和湖沼基因组之间。回交的结果揭示了一个惊人的模式的生态依赖：在沿岸的区，底栖回交增长率约为两倍的湖沼回交，而在开放水域，湖沼回交增长率约为两倍的底栖回交。这种逆转的相对健身的两个交叉类型在两个环境中提供了强有力的证据，不同的自然选择发挥了核心作用，底栖动物和湖沼动物之间的交配后隔离的演变。虽然在沿岸的区的所有杂交类型的增长率的排名顺序是底栖>底栖回交>湖沼回交>湖沼，没有回交显着不同的父母，它主要来自。这一结果的影响进行了讨论，在生态形态和可能的物种之间的渐渗杂交。结果在开放水域不太清楚，并不完全符合生态模式的物种，主要是由于低增长率的湖沼。然而，在开放水域的鱼的饮食分析表明，这些外壳可能没有完全成功地复制这个栖息地的食物制度的特点。通讯编辑：G.沃利斯
Abstract Ecological speciation occurs when reproductive isolation evolves ultimately as a result of divergent natural selection between populations inhabiting different environments or exploiting alternative resources. I tested a prediction of the ecological model concerning the fitness of hybrids between two young, sympatric species of threespine sticklebacks (Benthics and Limnetics). The two species are ecologically and morphologically divergent: the Benthic is adapted to feeding on invertebrates in the littoral zone of the lake whereas the Limnetic is adapted to feeding on zooplankton in the open water. The growth rate of two types of hybrids, the Benthic backcross and the Limnetic backcross, as well as both parent species, was evaluated in enclosures in both parental habitats in the lake. The use of backcrosses is ideal because a comparison of their growth rates in the two habitats estimates an ecologically dependent component of their fitness while controlling for any intrinsic genetic incompatibilities that may exist between the Benthic and Limnetic genomes. The backcross results revealed a striking pattern of ecological dependence: in the littoral zone, Benthic backcrosses grew at approximately twice the rate of Limnetic backcrosses, while in the open water, Limnetic backcrosses grew at approximately twice the rate of Benthic backcrosses. Such a reversal of relative fitness of the two cross-types in the two environments provides strong evidence that divergent natural selection has played a central role in the evolution of postmating isolation between Benthics and Limnetics. Although the rank order of growth rates of all cross-types in the littoral zone was Benthic > Benthic backcross > Limnetic backcross > Limnetic, neither backcross differed significantly from the parent from which it was mainly derived. Implications of this result are discussed in terms of ecological speciation and possible introgressive hybridization between the species. Results in the open water were less clear and were not fully consistent with the ecological model of speciation, mainly as a result of the low growth rate of Limnetics. However, analysis of the diet of the fish in the open water suggests that these enclosures may not have been fully successful at replicating the food regimes characteristic of this habitat. Corresponding Editor: G. Wallis