Phenotypic variation and sexual dimorphism in anadromous threespine stickleback: implications for postglacial adaptive radiation
Phenotypic variation and sexual dimorphism in anadromous threespine stickleback: implications for postglacial adaptive radiation
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DOI：
10.1111/j.1095-8312.2008.01075.x
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发表时间：
2008-11-01
影响因子：
1.9
通讯作者：
Bell, Michael A.
中科院分区：
文献类型：
--
作者：
Aguirre, Windsor E.;Ellis, Kaitlyn E.;Bell, Michael A.
祖先的属性可以影响进化多样化的模式，但很少能直接观察到祖先。我们研究了一个代表该地区冰期后刺鱼种群祖先形式的后水相刺鱼种群的形态特征的变异和性别二型性。采用传统形态计量学和几何形态计量学相结合的方法，研究了阿拉斯加州库克湾兔子沟繁殖的后水种群的多年变异。主要的盔甲异常是极其罕见的，但它们以可测量的频率出现表明，背水区种群的盔甲表型存在显着的立地差异。性别差异是变异的一个主要来源，大多数特征在性别之间存在显著差异，特别是头部长度、骨盆腰带长度和体型。因此，某种程度的性二型性似乎是源自淡水刺鱼辐射的许多特征的祖先条件。性别间形态差异显著，尤其是体型差异显著，但由于其他因素的影响，其年变化幅度总是较小。表型平均数在短时间尺度上相对稳定。冰川后刺鱼辐射是适应性辐射的最有启发性的例子之一，我们对回流刺鱼种群变异的详细研究提供了对适应性辐射的一个关键组成部分的重要洞察，即在辐射开始时定向选择所作用的变异。(C)2008年伦敦林尼安学会，《林尼安学会生物杂志》，2008年，95,465-478。
Ancestral properties can influence patterns of evolutionary diversification, but ancestors can rarely be observed directly. We examined variation and sexual dimorphism of morphological traits in an anadromous threespine stickleback population representing the ancestral form for resident postglacial stickleback populations in the area. A combination of traditional and geometric morphometric methods were used to study variation over multiple years in an anadromous population that breeds in Rabbit Slough, Cook Inlet, Alaska. Major armor anomalies were extremely rare but their occurrence at measurable frequencies suggests that significant standing variation for armor phenotypes exists in anadromous populations. Sexual dimorphism was a major source of variation, and most traits differed significantly between sexes, particularly head length, length of the pelvic girdle, and body shape. Consequently, some degree of sexual dimorphism appears to be the ancestral condition for many traits in derived resident freshwater stickleback radiations. Morphological variation among years, especially in body shape, was significant in both sexes, but the magnitude of annual variation was always less than variation due to other factors. Phenotypic means were relatively stable over short time scales. Postglacial stickleback radiations are among the most enlightening cases of adaptive radiation, and our detailed study of variation in an anadromous stickleback population provides crucial insight into a key component of adaptive radiation, the variation on which directional selection acts at the onset of the radiation. (c) 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 95, 465-478.