Biogeographic Variation in an Intertidal Predator-Prey Interaction: Does Coastal Oceanography Alter the Adaptive Landscape?

越来越多的分子研究表明，海洋种群之间的扩散和基因流动往往比传统认识的要少。然而，到目前为止，我们对亚种群之间的连通性降低如何影响海洋群落的生态和进化知之甚少。理论表明，当基因流动受到限制时，沿海岸线分布的底栖生物种群可能会对选择压力的空间变化做出反应。最近的工作强调了海洋过程（如沿海上升流）对底栖生物物种的补充、生长和繁殖的生态影响。由于这些自下而上的影响通常在空间上是一致的，它们也可能在当地社区的动态中留下重要的进化特征。特别是，在不同海洋学环境中共存的物种可能通过当地适应而形成不同的相互作用。槽螺（英文名Nucella canaliculata）是一种食肉腹足类动物，生活在北美洲太平洋沿岸潮间带贻贝加利福尼亚螺（Mytilus californianus）的波浪床上。在加利福尼亚海岸，纽塞拉经常钻这种贻贝。相比之下，海螺很少以俄勒冈海岸的加利福尼亚螺为食。先前的研究表明，这种钻孔行为的显著差异可能有遗传基础，线粒体序列的变化证实了这种海螺种群之间的基因流动较低。此外，这种海螺-贻贝的相互作用发生在数百公里之外的潮间带群落中，这些群落由于沿海上升流强度的区域差异而差异很大。因此，Nucella-Mytilus相互作用是在海洋过程空间变化的背景下研究当地适应的维持和后果的理想系统。一套协调的实地和实验室研究将用于评估五个假设：-螺钻行为的变化具有遗传基础。-钻井行为的纬度变化是由局部适应引起的；钻孔品种在其原生地点比在国外地点具有更高的适应性。本地适应模式是由贻贝（Mytilus trossulus）和加州贻贝（m.c californianus）的相对丰度所介导的适应性权衡所驱动的。-在加州和俄勒冈州，无肢猎物的数量和数量差别很大。这种海螺-贻贝相互作用的纬度变化具有重要的群落水平后果。越来越多的证据表明，海洋种群之间的遗传分化突出了理解海洋系统中基因流动受限的后果的重要性。通过整合生态学和进化方法，本研究将增加我们对当地适应如何在海洋群落动态中产生生物地理变异的理解。更广泛的影响涉及培训本科生，包括来自少数民族和代表性不足群体的REU学生。此外，该项目将在Bodega海洋实验室的教育和推广工作中得到强调，包括项目、旅游和公共展示。

A growing body of molecular studies suggests that dispersal and gene flow among marine populations are often less than traditionally recognized. However, to date, we know very little about how reduced connectivity among subpopulations influences the ecology and evolution of marine communities. Theory suggests that when gene flow is restricted, benthic populations distributed along a coastline may respond to spatial variation in selection pressures. Recent work highlights the ecological effects that oceanographic processes such as coastal upwelling can have on the recruitment, growth, and reproduction of benthic species. Because these bottom-up effects are often spatially consistent, they may also leave an important evolutionary signature on the dynamics of local communities. In particular, species that co-occur in different oceanographic regimes may have interactions that are shaped differently through local adaptation. The Channeled Whelk, Nucella canaliculata, is a predatory gastropod found living along the Pacific coast of North America in wave-exposed beds of the intertidal mussel Mytilus californianus. Along the coast of California, Nucella frequently drills this mussel. In contrast, whelks rarely feed on M. californianus along the Oregon coast. Previous work suggests that this striking difference in drilling behavior may have a genetic basis, and mitochondrial sequence variation confirms that gene flow is low among populations of this whelk. Moreover, this whelk-mussel interaction occurs over hundreds of kilometers, embedded within intertidal communities that differ dramatically as a result of regional variation in the intensity of coastal upwelling. The Nucella-Mytilus interaction is thus an ideal system for examining the maintenance and consequences of local adaptation within the context of spatial variation in oceanographic processes. A set of coordinated field and laboratory studies will be used to evaluate five hypotheses: - Variation in whelk drilling behavior has a genetic basis. - Latitudinal variation in drilling behavior arises through local adaptation; drilling varieties experience higher fitness at their native sites than at foreign sites. - Patterns of local adaptation are driven by a fitness trade-off mediated by the relative abundance of the mussels Mytilus trossulus and M. californianus.- The recruitment and abundance of sessile prey differ sharply between California and Oregon. - Latitudinal variation in this whelk-mussel interaction has important community-level consequences. Growing evidence of genetic differentiation among marine populations highlights the importance of understanding the consequences of restricted gene flow in marine systems. By integrating ecological and evolutionary approaches, the proposed research will increase our understanding of how local adaptation may generate biogeographic variation in the dynamics of marine communities. The broader impacts involve training undergraduates including REU students from minority and underrepresented groups. In addition, this project will be highlighted in education and outreach efforts including programs, tours, and public displays at Bodega Marine Laboratory.