Historical contingency shapes adaptive radiation in Antarctic fishes
Historical contingency shapes adaptive radiation in Antarctic fishes
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DOI：
10.1038/s41559-019-0914-2
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发表时间：
2019-07-01
影响因子：
16.8
通讯作者：
Harris, Matthew P.
中科院分区：
文献类型：
--
作者：
Daane, Jacob M.;Dornburg, Alex;Harris, Matthew P.
适应性辐射说明了生态机会、自然选择和生物多样性的产生之间的联系。适应性辐射的核心是多样化谱系与促进新环境或资源利用的表型变异进化之间的关联。然而，目前尚不清楚是适应性进化还是历史偶然性对适应性辐射中关键表型性状的起源更重要。在这里，我们使用超过250，000个基因座的46个物种的靶向测序，以检查有关南极notothenioid鱼类适应性辐射中关键性状的起源和多样性的假设。与适应性进化的预期相反，我们表明，在南大洋极地条件出现之前，notothenioids经历了基因组多样化的间歇性爆发，并进化出关键的骨骼修饰。我们发现，多样化的选择与人类骨骼发育不良的途径，促进生态重要的变化，浮力南极notothenioid物种之间，并证明足够的改变trip11，col1a2和col1a1a的功能在斑马鱼（斑马鱼）的表型骨骼减少南极notothenioid。而不是适应被驱动的南极冷却，我们的研究结果突出了历史偶然性的作用，在塑造适应性辐射的notothenioids。了解适应性辐射关键特征起源的历史和环境背景，不仅可以重建导致进化创新的事件，还可以预测气候变化对自然种群稳定性和可进化性的影响。
Adaptive radiation illustrates links between ecological opportunity, natural selection and the generation of biodiversity. Central to adaptive radiation is the association between a diversifying lineage and the evolution of phenotypic variation that facilitates the use of new environments or resources. However, is not clear whether adaptive evolution or historical contingency is more important for the origin of key phenotypic traits in adaptive radiation. Here we use targeted sequencing of >250,000 loci across 46 species to examine hypotheses concerning the origin and diversification of key traits in the adaptive radiation of Antarctic notothenioid fishes. Contrary to expectations of adaptive evolution, we show that notothenioids experienced a punctuated burst of genomic diversification and evolved key skeletal modifications before the onset of polar conditions in the Southern Ocean. We show that diversifying selection in pathways associated with human skeletal dysplasias facilitates ecologically important variation in buoyancy among Antarctic notothenioid species, and demonstrate the sufficiency of altered trip11, col1a2 and col1a1a function in zebrafish (Danio rerio) to phenocopy skeletal reduction in Antarctic notothenioids. Rather than adaptation being driven by the cooling of the Antarctic, our results highlight the role of historical contingency in shaping the adaptive radiation of notothenioids. Understanding the historical and environmental context for the origin of key traits in adaptive radiations extends beyond reconstructing events that result in evolutionary innovation, as it also provides a context in forecasting the effects of climate change on the stability and evolvability of natural populations.