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

许多物种已经进化出适应纬度气候梯度的能力，研究这些有助于了解物种如何进化以应对全球气候变化。为了研究智利银鱼的适应性，来自智利海岸沿着四个地方的野生鱼类的后代在四个常见的温度下饲养。不同纬度地区的种群在生长速度、脊椎动物数量和汞吸收量方面的差异表明，由于当地的适应，存在遗传差异。研究团队正在将这些智利银汉鱼数据与之前来自北方银汉鱼物种的数据进行整合，以更好地了解气候梯度强度与适应强度之间的关系。 该项目通过美国-智利研究生跨文化交流为两名研究生提供培训。这项研究正在被纳入在智利教授的研究生和本科生课程，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形式的当地适应的理解，即同梯度变化（CoGV）和反梯度变化（CnGV），这是适应大尺度纬度气候梯度的基础。利用一个普通的花园实验，该团队正在研究温度与智利银汉鱼遗传变异之间的关系。从智利海岸沿着的四个地点的野生创始人那里获得的新受精的后代正在四个共同的温度下饲养到一个共同的少年大小。种群间性状测量（生长能力、脊椎数量和总汞浓度）的差异，以检验1）生长能力随温度和纬度增加（CnGV）和2）脊椎数量随纬度增加（CoGV）的假设。这些数据正在与现有的证据整合从北方银汉鱼物种，以确定是否有CnGV/CoGV强度和纬度梯度strengths.This奖项之间的关系反映了NSF的法定使命，并已被认为是值得通过评估使用基金会的智力价值和更广泛的影响审查标准的支持。

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.