Degeneracy: A design principle for achieving robustness and evolvability

JOURNAL OF THEORETICAL BIOLOGY

卷:263

Article

Whitacre, James¹  Bender, Axel² 

[1] Univ New S Wales, Australian Def Force Acad, Def & Secur Applicat Res Ctr, Canberra, ACT, Australia

[2] Def Sci & Technol Org, Land Operat Div, Edinburgh, Australia

关键词: Evolution;    Fitness landscapes;    Neutral networks;    Redundancy;    Distributed robustness;   

DOI  :  10.1016/j.jtbi.2009.11.008

来源: Elsevier

【 摘 要 】

Robustness, the insensitivity of some of a biological system's functionalities to a set of distinct conditions, is intimately linked to fitness. Recent studies suggest that it may also play a vital role in enabling the evolution of species. Increasing robustness, so is proposed, can lead to the emergence of evolvability if evolution proceeds over a neutral network that extends far throughout the fitness landscape. Here, we show that the design principles used to achieve robustness dramatically influence whether robustness leads to evolvability. In simulation experiments, we find that purely redundant systems have remarkably low evolvability while degenerate, i.e. partially redundant, systems tend to be orders of magnitude more evolvable. Surprisingly, the magnitude of observed variation in evolvability can neither be explained by differences in the size north etopology of the neutral networks. This suggests that degeneracy, a ubiquitous characteristic in biological systems, may be an important enabler of natural evolution. More generally, our study provides valuable new clues a bout the origin of innovations in complex adaptive systems. (C) 2009 Elsevier Ltd. All rights reserved.

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