适应辐射是指由于环境变化而出现生态机遇时，某一生物支系由此快速演变产生多种多样、各自适应于独特生态位的物种或者群体的过程；导致不同生态位物种或群体间的趋异进化和相似生态位物种间的趋同进化或群体间的平行进化；是产生生物多样性的重要方式。尽管自然界中不乏适应辐射的例子，但适应辐射仅发生在某些特定的生物类群中。因为适应辐射的发生，不仅需要生态机遇而且需要相应的遗传基础，即生物面对生态机遇时需要迅速地产生可遗传的表型改变及遗传创新从而与环境相互作用以利用生态机遇。因此，适应辐射发生的遗传基础一直是进化生物学的热点研究之一。本申请拟以发生适应辐射的刺鱼类群为对象，运用群体基因组学和比较基因组学的方法，研究全球范围内刺鱼从海水向淡水适应辐射过程中种内平行进化与种间趋同进化的遗传基础。研究结果不但有助于我们理解适应辐射的发生，而且有助于我们揭示生物进化的一般规律，即生物进化的可重复性以及可预测性。

Adaptive radiation refers to the process that certain organismal linage has exhibited an exceptional extent of adaptive diversification into a variety of ecological niches when environmental changes result in ecological opportunity, with such divergence often occurring extremely rapidly. Adaptive radiation generates both disparities – divergent evolution among species and/or among populations within species in different ecological niches, and similarities – convergent evolution among species and parallel evolution among populations within species in geographically independent but ecologically similar niches. Adaptive radiations play key roles in the generation of biodiversity. Although adaptive radiation is not rare in wild, it occurs in only certain organismal linages. It is due to that adaptive radiation is not only is triggered by accessing to novel ecological opportunity, but also requires underlying genetic basis that can relatively rapidly generate phenotypic modifications and innovations to utilize ecological opportunity. Therefore, understanding the genetic basis that drive adaptive radiation has long been the hotspot topic of evolutionary biology. In this proposal, I propose to use the sticklebacks (Gasterosteidae) – a represent model of adaptive radiation to investigate the genetic basis of adaptive radiation in wild. I will combine both population genomics and comparative genomics approaches to investigate the genetic basis of parallel evolution with species and convergent evolution between species for their adaptive radiation from marine to freshwater in sticklebacks in a global scale. The expected results would not only help us better understanding the occurrence of adaptive radiation, but also provide us an opportunity to address the general question in evolutionary biology – repeatability and predictability of evolution.