The origins of novelty from within the confines of homology: the developmental evolution of the digging tibia of dung beetles
The origins of novelty from within the confines of homology: the developmental evolution of the digging tibia of dung beetles
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DOI：
10.1098/rspb.2018.2427
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发表时间：
2019-02-06
影响因子：
4.7
通讯作者：
Moczek, Armin P.
中科院分区：
文献类型：
--
作者：
Linz, David M.;Hu, Yonggang;Moczek, Armin P.
了解新的复杂性状的起源是进化生物学最基本的目标之一。进化中最广泛使用的新颖性定义假设同源性的缺失，然而随着进化不断修正我们对同源性的理解，同源性的结束和新颖性的开始越来越难以解析。在这里，我们进行了一个案例研究，探讨创新的最早阶段，通过检查的胫骨齿的隧道粪甲虫。胫骨齿是一种形态学上适度的创新，由相对简单的体壁突起组成，完全包含在胫骨前部，胫骨前部是一个腿段，其自身的同源性状态是明确的。我们首先证明，胫骨齿援助在多种挖掘行为。然后，我们表明，胫骨牙齿的发育进化是由本地预先存在的基因网络的重新部署。与此同时，我们发现，即使在这个创新的早期阶段，至少有两个基因在胚胎模式中起作用，因此完全在腿部形成的时空背景之外，已经被招募来帮助塑造胫骨牙齿的形成。我们的研究结果提出了一个可测试的模型，发展进化支架创新。
Understanding the origin of novel complex traits is among the most fundamental goals in evolutionary biology. The most widely used definition of novelty in evolution assumes the absence of homology, yet where homology ends and novelty begins is increasingly difficult to parse as evo devo continuously revises our understanding of what constitutes homology. Here, we executed a case study to explore the earliest stages of innovation by examining the tibial teeth of tunnelling dung beetles. Tibial teeth are a morphologically modest innovation, composed of relatively simple body wall projections and contained fully within the fore tibia, a leg segment whose own homology status is unambiguous. We first demonstrate that tibial teeth aid in multiple digging behaviours. We then show that the developmental evolution of tibial teeth was dominated by the redeployment of locally pre-existing gene networks. At the same time, we find that even at this very early stage of innovation, at least two genes that ancestrally function in embryonic patterning and thus entirely outside the spatial and temporal context of leg formation, have already become recruited to help shape the formation of tibial teeth. Our results suggest a testable model for how developmental evolution scaffolds innovation.