Erwin Douglas H
Department of Paleobiology, MRC-121 National Museum of Natural History, PO Box 37012, Washington, DC 20013-7012, USA.
Curr Biol. 2015 Oct 5;25(19):R930-40. doi: 10.1016/j.cub.2015.08.019.
The history of life as documented by the fossil record encompasses evolutionary diversifications at scales ranging from the Ediacaran-Cambrian explosion of animal life and the invasion of land by vascular plants, insects and vertebrates to the diversification of flowering plants over the past 100 million years and the radiation of horses. Morphological novelty and innovation has been a recurrent theme. The architects of the modern synthesis of evolutionary theory made three claims about evolutionary novelty and innovation: first, that all diversifications in the history of life represent adaptive radiations; second, that adaptive radiations are driven principally by ecological opportunity rather than by the supply of new morphological novelties, thus the primary questions about novelty and innovation focus on their ecological and evolutionary success; and third, that the rate of morphological divergence between taxa was more rapid early in the history of a clade but slowed over time as ecological opportunities declined. These claims have strongly influenced subsequent generations of evolutionary biologists, yet over the past two decades each has been challenged by data from the fossil record, by the results of comparative phylogenetic analyses and through insights from evolutionary developmental biology. Consequently a broader view of novelty and innovation is required. An outstanding issue for future work is identifying the circumstances associated with different styles of diversification and whether their frequency has changed through the history of life.
化石记录所记载的生命史涵盖了从埃迪卡拉纪-寒武纪动物生命大爆发、维管植物、昆虫和脊椎动物登陆，到过去一亿年开花植物的多样化以及马的辐射演化等不同尺度的进化多样化过程。形态新奇性和创新性一直是一个反复出现的主题。现代进化理论综合学说的创立者们对进化新奇性和创新性提出了三个观点：第一，生命史上所有的多样化都代表适应性辐射；第二，适应性辐射主要由生态机遇驱动，而非新形态新奇性的供应，因此关于新奇性和创新性的主要问题集中在它们的生态和进化成功上；第三，类群之间形态差异的速率在一个进化枝历史的早期更快，但随着生态机遇的减少而随时间减缓。这些观点对后世的进化生物学家产生了强烈影响，然而在过去二十年里，每一个观点都受到了来自化石记录的数据、比较系统发育分析结果以及进化发育生物学见解的挑战。因此，需要对新奇性和创新性有更广泛的认识。未来工作的一个突出问题是确定与不同多样化方式相关的情况，以及它们的频率在生命史上是否发生了变化。
