Lab of Control and Systems Biology, Department of Electrical Engineering, National Tsing Hua University, Hsinchu, Taiwan 30013.
Evol Bioinform Online. 2011;7:201-33. doi: 10.4137/EBO.S8123. Epub 2011 Nov 1.
In the evolutionary process, the random transmission and mutation of genes provide biological diversities for natural selection. In order to preserve functional phenotypes between generations, gene networks need to evolve robustly under the influence of random perturbations. Therefore, the robustness of the phenotype, in the evolutionary process, exerts a selection force on gene networks to keep network functions. However, gene networks need to adjust, by variations in genetic content, to generate phenotypes for new challenges in the network's evolution, ie, the evolvability. Hence, there should be some interplay between the evolvability and network robustness in evolutionary gene networks. In this study, the interplay between the evolvability and network robustness of a gene network and a biochemical network is discussed from a nonlinear stochastic system point of view. It was found that if the genetic robustness plus environmental robustness is less than the network robustness, the phenotype of the biological network is robust in evolution. The tradeoff between the genetic robustness and environmental robustness in evolution is discussed from the stochastic stability robustness and sensitivity of the nonlinear stochastic biological network, which may be relevant to the statistical tradeoff between bias and variance, the so-called bias/variance dilemma. Further, the tradeoff could be considered as an antagonistic pleiotropic action of a gene network and discussed from the systems biology perspective.
在进化过程中，基因的随机传递和突变为自然选择提供了生物多样性。为了在随机扰动的影响下保持代际之间的功能表型，基因网络需要稳健进化。因此，表型的稳健性在进化过程中对基因网络施加了选择压力，以保持网络功能。然而，基因网络需要通过遗传内容的变化来调整，以产生新的网络进化挑战的表型，即可进化性。因此，在进化基因网络中，应该存在可进化性和网络稳健性之间的相互作用。在这项研究中，从非线性随机系统的角度讨论了基因网络和生化网络的可进化性和网络稳健性之间的相互作用。结果发现，如果遗传稳健性加上环境稳健性小于网络稳健性，则生物网络的表型在进化中是稳健的。从非线性随机生物网络的随机稳定性稳健性和敏感性角度讨论了进化中遗传稳健性和环境稳健性之间的权衡，这可能与偏差和方差之间的统计权衡有关，即所谓的偏差/方差困境。此外，这种权衡可以被认为是基因网络的拮抗多效性作用，并从系统生物学的角度进行讨论。
