Spontaneous evolution of modularity and network motifs
Spontaneous evolution of modularity and network motifs
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DOI：
10.1073/pnas.0503610102
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发表时间：
2005-09-27
影响因子：
11.1
通讯作者：
Alon, U
中科院分区：
文献类型：
--
作者：
Kashtan, N;Alon, U
生物网络具有固有的简单性：它们是模块化的，其设计可以分成几乎独立执行的单元。此外，它们还显示了被称为网络基序的重复模式的重用。人们对这些特性的进化起源知之甚少。目前的生物进化模型通常产生高度非模块化的网络，缺乏可理解的基序。在这里，我们提出了一个可能的解释起源的模块化和网络基序在生物学。我们使用标准的进化算法来进化网络。本研究的一个关键特征是在一个以模块化方式变化的环境（进化目标）下的进化。也就是说，我们在几个目标之间反复切换，每个目标都由不同的子目标组合组成。我们发现，这种“模块化变化的目标”导致了模块化网络结构和网络基序的自发进化。由此产生的网络迅速发展以满足每个不同的目标。在相关目标之间的这种转换可能代表了在不断变化的环境中的生物进化，这种环境需要一组基本生物功能的不同组合。目前的研究可能揭示了促进生物网络结构简单性的进化力量，并提供了改进工程系统进化设计的方法。
Biological networks have an inherent simplicity: they are modular with a design that can be separated into units that perform almost independently. Furthermore, they show reuse of recurring patterns termed network motifs. Little is known about the evolutionary origin of these properties. Current models of biological evolution typically produce networks that are highly nonmodular and lack understandable motifs. Here, we suggest a possible explanation for the origin of modularity and network motifs in biology. We use standard evolutionary algorithms to evolve networks. A key feature in this study is evolution under an environment (evolutionary goal) that changes in a modular fashion. That is, we repeatedly switch between several goals, each made of a different combination of subgoals. We find that such "modularly varying goals" lead to the spontaneous evolution of modular network structure and network motifs. The resulting networks rapidly evolve to satisfy each of the different goals. Such switching between related goals may represent biological evolution in a changing environment that requires different combinations of a set of basic biological functions. The present study may shed light on the evolutionary forces that promote structural simplicity in biological networks and offers ways to improve the evolutionary design of engineered systems.