RAPID: Behavioral Plasticity and Hybridization of Young Species

由于人类对环境的改变，生物多样性正在以极快的速度减少。人类活动的一个结果是提高了水生环境的生产力，往往导致包括三刺鱼在内的水生生物的生长速度发生变化。这种小鱼已经成为了解新出现的物种如何进化以及它们如何保持其独特性的模型。这里提出的研究将评估太平洋西北部少数湖泊中出现的物种对构成的威胁，重点是身体大小和行为可能发生的变化。这项研究不仅对刺鱼具有重要的保护意义，还有助于理解人类造成的环境变化导致的体型和行为变化，最终导致物种之间的杂交和生物多样性的丧失。这项研究将包括实地和实验室研究的本科生和研究生。这些发现将被纳入克拉克大学的本科教学，并被纳入克拉克大学所在的主要贫困和少数族裔社区的小学到高中生的推广活动中。物种形成的初始阶段很难捕捉，但来自太平洋西北部的三刺鱼(Gastersteus Aculeatus)已经成为物种形成过程的模型系统。复制的物种对详细揭示了与分歧相关的遗传、形态和行为转变。有时，当种群暴露在新的环境中时，物种形成的初始阶段受到行为和形态上的可塑性变化的影响。可塑性转变之后可能伴随着遗传适应，导致种群的进化分化，并导致稳定的生殖隔离。然而，在某些情况下，可以通过在次生共生中不同地利用生境来维持生殖隔离，而不需要显著的遗传分化，导致环境变化可能会促进杂交和近亲物种的丧失。这是一种在尖吻海绵的种对中没有探索过的可能性。身体大小的差异是雌雄之间生殖隔离的重要中介。这项研究将评估由于水生生产力的提高，物种对之间的体型差异正在缩小的可能性，以及这可能导致不列颠哥伦比亚省南部剩余的三个底栖-滩涂物种对的杂交。这项研究的时机至关重要，因为众所周知，这个系统的进化速度很快，可能导致其灭亡的环境变化也是如此。这些物种对提供了对生态物种形成机制的无与伦比的洞察，它们通过杂交的损失将掩盖它们提供的早期分歧的众多生物学特征。所有数据都将存档在仙女座数字储存库中。

Biological diversity is decreasing at an exceptionally rapid rate in response to human modification of the environment. One outcome of human activity is increasing productivity in aquatic environments, often leading to changes in growth rates of aquatic organisms including the threespine stickleback fish. This small fish has served as a model for understanding how newly-arisen species have evolved and how they maintain their distinctiveness. The research proposed here will evaluate the threat posed to pairs of species that have arisen in a small number of lakes in the Pacific Northwest, focusing on possible shifts in body size and behavior. The research has significant conservation implications not just for stickleback but also for understanding human-caused environmental changes leading to size and behavioral shifts, and, ultimately, interbreeding between species and loss of biodiversity. The research will include undergraduates and graduate students in field and laboratory research. The findings will be incorporated into teaching at the undergraduate level at Clark University and into outreach activities involving elementary school through high school students in the largely impoverished and minority community in which Clark University is located.The initial stages of speciation are difficult to capture, but the threespine stickleback fish (Gasterosteus aculeatus) from the Pacific Northwest has served as a model system of the speciation process. Replicated pairs of species have revealed in detail the genetic, morphological, and behavioral transitions associated with divergence. Sometimes, the initial stages of speciation are mediated by plastic shifts in behavior and morphology, when populations are exposed to novel environments. Plastic transitions may be followed by genetic accommodation, leading to evolutionary differentiation of the populations, and to stable reproductive isolation. In some instances however, reproductive isolation can be maintained by differential use of habitats in secondary sympatry, without significant genetic differentiation, leading to the possibility that changing environments will facilitate hybridization and loss of closely related species. This is a possibility that has not been explored in the species pairs of G. aculeatus. Differences in body size are important mediators of reproductive isolation between members of the pairs. This research will evaluate the possibility that differences in body size between the species pairs is decreasing due to increasing aquatic productivity and that this could lead to hybridization of the three remaining benthic-limnetic species pairs in southern British Columbia. The timing of the research is critical, as evolution in this system is known to be rapid, as is the environmental change that could cause its demise. These species pairs have offered unparalleled insight into the mechanisms of ecological speciation, and their loss through hybridization will conceal the numerous biological signatures of early divergence they have provided. All data will be archived in the Dryad Digital Repository.