Solé Ricard V, Valverde Sergi
Complex Systems Lab, ICREA-UPF, Dr Aiguader 88, 08003 Barcelona, Spain.
J R Soc Interface. 2008 Jan 6;5(18):129-33. doi: 10.1098/rsif.2007.1108.
Modularity is known to be one of the most relevant characteristics of biological systems and appears to be present at multiple scales. Given its adaptive potential, it is often assumed to be the target of selective pressures. Under such interpretation, selection would be actively favouring the formation of modular structures, which would specialize in different functions. Here we show that, within the context of cellular networks, no such selection pressure is needed to obtain modularity. Instead, the intrinsic dynamics of network growth by duplication and diversification is able to generate it for free and explain the statistical features exhibited by small subgraphs. The implications for the evolution and evolvability of both biological and technological systems are discussed.
模块化是生物系统最相关的特征之一，且似乎存在于多个尺度。鉴于其适应潜力，人们通常认为它是选择压力的目标。在这种解释下，选择会积极促进模块化结构的形成，这些结构将专门执行不同的功能。在这里我们表明，在细胞网络的背景下，获得模块化不需要这样的选择压力。相反，通过复制和多样化实现的网络增长的内在动力学能够免费生成模块化，并解释小子图所展现的统计特征。本文还讨论了这对生物和技术系统的进化及演化能力的影响。
