Expanding the silverside system to quantify how climate gradients determine co- and countergradient adaptation strength in the ocean

许多物种已经进化到适应纬度气候梯度，研究这些揭示了物种将如何进化以应对全球气候变化。为了调查智利银鱼的适应性，来自智利海岸四个地点的野生鱼的后代在四个共同的温度下饲养。在不同纬度的种群中，生长速度、椎体数目和汞摄取的差异表明由于局部适应而产生的遗传差异。研究小组正在将这些智利银鱼的数据与北半球银鱼物种的先前数据相结合，以更好地了解气候梯度强度与适应强度之间的关系。本项目通过美智研究生跨文化交流项目为两名研究生提供培训。这项研究正在整合到智利的研究生和本科生课程中，研究小组正在通过网站和杂志文章与公众分享研究结果。该项目促进了对两种局部适应形式的理解，即共梯度变化（CoGV）和反梯度变化（CnGV），它们是适应大尺度纬度气候梯度的基础。通过一个普通的花园实验，研究小组正在研究智利银边鱼的温度和基因变异之间的关系。从智利海岸四个地点的野生创始人那里获得的新受精的后代在四个共同的温度下饲养，直到一个共同的幼崽大小。种群间性状测量（生长量、椎体数和总汞浓度）的差异，以检验1)生长量随温度和纬度增加（CnGV）和2)椎体数随纬度增加（CoGV）的假设。这些数据正在与北半球银鱼物种的现有证据相结合，以确定CnGV/CoGV强度与纬向梯度强度之间是否存在关系。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Many species have evolved adaptations to latitudinal climate gradients and studying these sheds light on how species will evolve in response to global climate change. To investigate adaptation in Chilean silversides, offspring of wild fish from four locations along the Chilean coast are being reared at four common temperatures. Differences in growth rates, vertebral number, and mercury uptake among populations from different latitudes indicate genetic differences due to local adaptation. The research team is integrating these Chilean silverside data with prior data from northern hemisphere silverside species to better understand the relationship between climate gradient strength and adaptation strength. This project provides training for two graduate students through a US-Chile graduate cross-cultural exchange. The research is being integrated into graduate and undergraduate courses taught in Chile and the research team is sharing the results with the public through a website and magazine articles. This project advances understanding of two forms of local adaptation, co-gradient variation (CoGV) and counter-gradient variation (CnGV), which underlie adaptation to large-scale, latitudinal climate gradients. Using a common garden experiment, the team is examining the relationship between temperature and genetic variation in Chilean silversides. Newly-fertilized offspring obtained from wild founders at four locations along the Chilean coast are being reared at four common temperatures to a common juvenile size. Differences among populations in trait measurements (growth capacity, vertebral number, and total mercury concentration) to test the hypotheses that 1) growth capacity increases with temperature and latitude (CnGV) and 2) vertebral number increases with latitude (CoGV). These data are being integrated with existing evidence from northern hemisphere silverside species to determine if there is a relationship between CnGV/CoGV strength and latitudinal gradient strength.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.