RAPID: Behavioral Plasticity and Hybridization of Young Species

由于人类对环境的改变，生物多样性正以异常迅速的速度减少。人类活动的一个结果是提高了水生环境的生产力，经常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物种如何进化以及如何保持其独特性的模型。这里提出的研究将评估对太平洋西北部少数湖泊中出现的成对物种构成的威胁，重点关注体型和行为可能发生的变化。这项研究不仅对棘鱼有重要的保护意义，而且对理解人类造成的环境变化导致的大小和行为变化，以及物种之间的杂交和生物多样性的丧失也有重要的意义。该研究将包括本科生和研究生的实地和实验室研究。研究结果将被纳入克拉克大学本科阶段的教学，并纳入克拉克大学所在的以贫困和少数民族为主的社区的小学到高中学生的推广活动。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棘鱼（Gasterosteus aculeatus）已成为物种形成过程的模型系统。物种复制对详细揭示了与分化相关的遗传、形态和行为转变。有时，当种群暴露于新环境时，物种形成的初始阶段是由行为和形态的塑性变化介导的。可塑性转变之后可能是遗传适应，导致种群的进化分化和稳定的生殖隔离。然而，在某些情况下，生殖隔离可以通过在次级同栖生物中不同地利用生境来维持，而没有显著的遗传分化，从而导致环境的变化可能促进杂交和密切相关物种的丧失。这是一种可能性，尚未探讨的物种对的刺毛鳗。身体大小的差异是对成员之间生殖隔离的重要媒介。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减少的可能性，这可能导致不列颠哥伦比亚省南部剩余的三个底栖物种对杂交。研究的时机至关重要，因为众所周知，这个系统的进化是迅速的，环境变化也可能导致它的灭亡。这些物种对对生态物种形成的机制提供了无与伦比的见解，它们在杂交过程中的损失将掩盖它们提供的早期分化的许多生物学特征。所有数据将被存档在Dryad数字存储库中。

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.