Mega-evolutionary dynamics of the adaptive radiation of birds.
Mega-evolutionary dynamics of the adaptive radiation of birds.
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DOI：
10.1038/nature21074
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发表时间：
2017-02-16
期刊：
影响因子：
64.8
通讯作者：
Thomas GH
中科院分区：
文献类型：
--
作者：
Cooney CR;Bright JA;Capp EJR;Chira AM;Hughes EC;Moody CJA;Nouri LO;Varley ZK;Thomas GH
生物多样性的起源和扩大既受发展轨迹的制约，也受现有生态位的限制。随着谱系的多样化，物种和特征繁殖的早期阶段通常是快速的，随着新物种涌入生态位空间中更密集的区域，物种和特征的扩散让位于进化的减慢。像达尔文雀类这样的小支系表明，自然选择是适应性辐射的驱动力，但微进化过程如何放大，以在更长的进化时间尺度上塑造表型多样性的扩展尚不清楚。在这里，我们解决这个问题在全球范围内通过分析一个新的人群来源的数据集的3D扫描钞票形态从>；2000物种。我们发现，喙多样性在现存鸟类进化史的早期就扩大了，然后过渡到以形态空间堆积为主的阶段。然而，这种早期的表型多样性与进化速度的时间变化是分离的：票据进化速度因谱系而异，但随着时间的推移相对稳定。我们发现，罕见但主要的表型不连续出现在沿着单个分支的速率的快速增加，有时导致具有不寻常的喙形态的恶化的分支。尽管在不同种群之间有这些跳跃，但不同鸟类内部喙形状进化的主轴是非常一致的。我们揭示了全球尺度适应性辐射背后的宏观进化过程，支持达尔文和辛普森关于适应区内的微观进化和不同适应峰之间的加速进化的观点。
The origin and expansion of biological diversity is regulated by both developmental trajectories and limits on available ecological niches. As lineages diversify an early, often rapid, phase of species and trait proliferation gives way to evolutionary slowdowns as new species pack into ever more densely occupied regions of ecological niche space. Small clades such as Darwin’s finches demonstrate that natural selection is the driving force of adaptive radiations, but how microevolutionary processes scale up to shape the expansion of phenotypic diversity over much longer evolutionary timescales is unclear. Here we address this problem on a global scale by analysing a novel crowd-sourced dataset of 3D-scanned bill morphology from >2000 species. We find that bill diversity expanded early in extant avian evolutionary history before transitioning to a phase dominated by morphospace packing. However, this early phenotypic diversification is decoupled from temporal variation in evolutionary rate: rates of bill evolution vary among lineages but are comparatively stable through time. We find that rare but major discontinuities in phenotype emerge from rapid increases in rate along single branches, sometimes leading to depauperate clades with unusual bill morphologies. Despite these jumps between groups, the major axes of within-group bill shape evolution are remarkably consistent across birds. We reveal that macroevolutionary processes underlying global-scale adaptive radiations support Darwinian and Simpsonian ideas of microevolution within adaptive zones and accelerated evolution between distinct adaptive peaks.