FORAGING TRAIT (CO)VARIANCES IN STICKLEBACK EVOLVE DETERMINISTICALLY AND DO NOT PREDICT TRAJECTORIES OF ADAPTIVE DIVERSIFICATION
FORAGING TRAIT (CO)VARIANCES IN STICKLEBACK EVOLVE DETERMINISTICALLY AND DO NOT PREDICT TRAJECTORIES OF ADAPTIVE DIVERSIFICATION
复制标题
DOI：
10.1111/j.1558-5646.2010.00982.x
复制
发表时间：
2010-08-01
期刊：
影响因子：
3.3
通讯作者：
Bolnick, Daniel I.
中科院分区：
文献类型：
--
作者：
Berner, Daniel;Stutz, William E.;Bolnick, Daniel I.
自然选择如何塑造多个性状之间的方差和协方差结构，以及(协方差)如何影响适应性多样化的轨迹？我们通过比较18个湖栖三刺鱼种群及其海洋祖先的多种形态特征之间的表型(Co)差异来研究这些关键但仍未解决的问题。种群间(协方差)结构的差异是显著的，主要归因于单一关键觅食性状(鳃钩长)的方差的变化。然后，我们将这种差异与生态选择代理、种群在性状均值上的差异以及种群内性别二型性的大小联系起来。这使我们能够推断，(Co)变异的进化与资源介导的破坏性选择的强度在不同生境之间的变异有关。我们进一步发现，群体间性状的适应性多样化主要涉及鳃长度的变化。进化轨迹的方向与祖先性状(Co)变异的主轴无关。我们的研究表明，自然选择在刺背中确定性地驱动均值和(协方差)方差，并强烈挑战了这样的观点，即(协方差结构)甚至在适度的时间跨度内也可预测地偏向适应性多样化的方向。
How does natural selection shape the structure of variance and covariance among multiple traits, and how do (co)variances influence trajectories of adaptive diversification? We investigate these pivotal but open questions by comparing phenotypic (co)variances among multiple morphological traits across 18 derived lake-dwelling populations of threespine stickleback, and their marine ancestor. Divergence in (co)variance structure among populations is striking and primarily attributable to shifts in the variance of a single key foraging trait (gill raker length). We then relate this divergence to an ecological selection proxy, to population divergence in trait means, and to the magnitude of sexual dimorphism within populations. This allows us to infer that evolution in (co)variances is linked to variation among habitats in the strength of resource-mediated disruptive selection. We further find that adaptive diversification in trait means among populations has primarily involved shifts in gill raker length. The direction of evolutionary trajectories is unrelated to the major axes of ancestral trait (co)variance. Our study demonstrates that natural selection drives both means and (co)variances deterministically in stickleback, and strongly challenges the view that the (co)variance structure biases the direction of adaptive diversification predictably even over moderate time spans.