Natural selection drives patterns of lake-stream divergence in stickleback foraging morphology
Natural selection drives patterns of lake-stream divergence in stickleback foraging morphology
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DOI：
10.1111/j.1420-9101.2008.01583.x
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发表时间：
2008-11-01
影响因子：
2.1
通讯作者：
Hendry, A. P.
中科院分区：
文献类型：
--
作者：
Berner, D.;Adams, D. C.;Hendry, A. P.
自然选择在多大程度上决定了生物多样性的模式？我们通过探索栖息在八个独立流域的湖泊和溪流栖息地的三刺鱼在觅食形态上的差异来解决这个问题。我们发现，湖鱼通常比溪流鱼表现出更发达的鳃结构和更流线型的身体。食物分析表明，这些形态差异与滩涂和底栖生物觅食模式有关，流域内形态差异的程度反映了湖泊和溪流鱼类利用猎物资源的差异。我们还发现，分化模式与群体内的表型性状(Co)变异模式(即“抗性最小的品系”)无关。相反，表型(Co)差异更有可能是由于对湖泊和溪流生境的适应而形成的。因此，我们的研究表明，自然选择是推动湖流刺鱼形态多样化的一种强大的决定性力量。这一推论的强度是通过用选择性力量的定量估计和性状(Co)方差的信息补充对离散生境类别(湖泊与溪流)之间的平均水平差异的标准分析而获得的。
To what extent are patterns of biological diversification determined by natural selection? We addressed this question by exploring divergence in foraging morphology of threespine stickleback fish inhabiting lake and stream habitats within eight independent watersheds. We found that lake fish generally displayed more developed gill structures and had more streamlined bodies than did stream fish. Diet analysis revealed that these morphological differences were associated with limnetic vs. benthic foraging modes, and that the extent of morphological divergence within watersheds reflected differences in prey resources utilized by lake and stream fish. We also found that patterns of divergence were unrelated to patterns of phenotypic trait (co)variance within populations (i.e. the 'line of least resistance'). Instead, phenotypic (co)variances were more likely to have been shaped by adaptation to lake vs. stream habitats. Our study thus implicates natural selection as a strong deterministic force driving morphological diversification in lake-stream stickleback. The strength of this inference was obtained by complementing a standard analysis of parallel divergence in means between discrete habitat categories (lake vs. stream) with quantitative estimates of selective forces and information on trait (co)variances.