Multivariate evolution in replicated adaptive radiations: pattern, process and the role of the environment.

生态学和进化论的研究是密切相关的。生态学家试图了解解释物种分布和丰度的环境因素，而进化生物学家则通过检查表型和基因类型的适应性来研究自然选择的过程和由此导致的进化。令人好奇的是，在这个环境变化的时代，我们对自然界的理解中最大的差距之一恰恰落在生态学和进化论的交汇点上：我们对环境如何塑造生物多样性进化的了解比我们应该知道的要少。虽然人们普遍认为环境是适应的原因，但它们之间的联系很少被明确探讨。许多生态学研究不考虑它们测量的环境变异如何影响进化，而许多进化研究测量选择或适应，而不考虑它们的环境原因，而是专注于遗传上可能的东西对进化的后果。对环境参与进化的显性研究有可能推动我们对基本进化模式的理解的范式转变。例如：(I)分歧。进化导致了自然界丰富的多样性，但在相关的有机体群体中，这种差异的程度往往是有限的。这些对进化生物种类的限制是遗传可能性的结果，还是生物暴露在环境中的相似性造成的？(Ii)衔接。在更大的分歧中，有机体往往明显地在类似的进化解决方案上趋同，这表明进化结果在某种程度上是可重复的。相似生物在不同地方的反复进化是遗传偏见的结果还是环境决定因素的结果？如果是后者，相似的生物体是否总是在相似的环境中进化，或者不同的环境是否有利于生物体形式的相同结果？反之亦然，相似的环境组合是否总是导致本质上相同的有机体，或者类似的环境问题是否存在不同的进化解决方案？(三)新颖性。尽管不同地方的相似生物往往会聚在反复进化的解决方案上，但进化偶尔也会通过发展或失去一些明显的特征或特征的组合，得出不同于一般模式的解决方案。这种进化的新颖性是不是特别不寻常的环境的结果？以前大多数关于环境如何影响进化的研究只衡量了有机体和环境的单个或少数方面，但要彻底回答我们提出的问题，需要更全面地了解有机体和环境的多个不同方面，以及它们如何相互作用和影响其他方面。我们的方法需要使用最近开发的多变量统计方法，这些方法允许同时分析许多生物特征和许多环境变量。适应性辐射是指将祖先物种分化为不同的新种群或物种。环境和生物多样性的丰富变化使适应性辐射成为解决我们问题的完美自然实验室。我们将使用苏格兰、冰岛、加拿大西部和阿拉斯加的三刺刺鱼的重复适应性辐射数据来回答我们的问题，并全面了解环境如何影响进化。三刺刺鱼最初是自上一个冰河时代以来入侵整个北半球淡水的海鱼。淡水刺鱼可以占据不同的环境，并表现出很大的表型变异，为我们的研究提供了一个完美的系统。

The studies of ecology and evolution are closely related. Ecologists seek to understand the environmental factors that explain the distribution and abundance of species, while evolutionary biologists investigate the process of natural selection and the evolution that results, by examination of adaptation in phenotypes and genotypes. It is curious in these times of environmental change that one of the biggest gaps in our understanding of the natural world falls exactly at the intersection between ecology and evolution: we know less than we should about how the environment shapes the evolution of biodiversity. Although it is generally understood that the environment is the cause of adaptation, the links between them have seldom been explicitly explored. Many ecological studies do not consider how the environmental variation that they measure affects evolution, while many studies of evolution measure selection or adaptation without considering their environmental causes, concentrating instead on the consequences for evolution of what is genetically possible.Explicit study of the involvement of the environment in evolution has the potential to fuel a paradigm shift in our comprehension of fundamental evolutionary patterns. For example: (i) Divergence. Evolution has resulted in abundant diversity in the natural world, but the extent of this divergence within related groups of organisms is often circumscribed. Are these limits, on the kind of organisms that evolve, a consequence of what is genetically possible, or do they result from similarities in the environments to which the organisms are exposed? (ii) Convergence. Within the greater divergence, organisms have often apparently converged on similar evolutionary solutions, suggesting that evolutionary outcomes are to some extent repeatable. Is the repeated evolution of similar organisms in different places the result of genetic biases or environmental determinants? If the latter, do similar organisms always evolve in similar environments, or can different environments favour the same outcome of organismal form? Vice versa, do similar environmental combinations always result in essentially the same organism, or are there different evolutionary solutions to similar environmental problems? (iii) Novelty. Although similar organisms in different places often converge on repeated evolutionary solutions, evolution also occasionally comes up with solutions that are different from the general pattern, by dint of developing, or having lost, some distinguishing feature or combination of features. Is such evolutionary novelty the result of particularly unusual environments? Most previous studies of how the environment affects evolution have measured only a single, or small number of aspects of both the organism and the environment, but thorough answers to the questions we pose require a more comprehensive understanding of multiple different aspects of organism and environment, and of how they interact and affect other. Our approach requires the use of recently developed multivariate statistical methods that allow the simultaneous analysis of many organismal traits and many environmental variables.Adaptive radiation is the differentiation of an ancestral species into divergent new populations or species. The abundance of variation in both environment and biodiversity make adaptive radiations the perfect natural laboratories to address our questions. We will use data from replicated adaptive radiations of three-spined stickleback fish in Scotland, Iceland, western Canada and Alaska in order to answer our questions and achieve a comprehensive understanding of how the environment affects evolution. Three-spined stickleback are originally marine fish that have invaded freshwater throughout the northern hemisphere since the last ice age. Freshwater stickleback can occupy contrasting environments and exhibit great phenotypic variation, providing a perfect system for our study.