Fuentes Miguel A, Krakauer David C
Santa Fe Institute, 1399 Hyde Park Road, Santa Fe, NM 87501, USA.
J R Soc Interface. 2008 Feb 6;5(19):237-45. doi: 10.1098/rsif.2007.1074.
Of considerable interest are the evolutionary and developmental origins of complex, adaptive structures and the mechanisms that stabilize these structures. We consider the relationship between the evolutionary process of gene duplication and deletion and the stability of morphogenetic patterns produced by interacting activators and inhibitors. We compare the relative stability of patterns with a single activator and inhibitor (two-dimensional system) against a 'redundant' system with two activators or two inhibitors (three-dimensional system). We find that duplication events can both expand and contract the space of patterns. We study developmental robustness in terms of stochastic escape times from this space, also known as a 'canalization potential'. We embed the output of pattern formation into an explicit evolutionary model of gene duplication, gene loss and variation in the steepness of the canalization potential. We find that under all constant conditions, the system evolves towards a preference for steep potentials associated with low phenotypic variability and longer lifespans. This preference leads to an overall decrease in the density of redundant genotypes as developmental robustness neutralizes the advantages of genetic robustness.
复杂适应性结构的进化和发育起源以及稳定这些结构的机制备受关注。我们考虑基因复制和缺失的进化过程与由相互作用的激活剂和抑制剂产生的形态发生模式稳定性之间的关系。我们比较了具有单一激活剂和抑制剂的模式（二维系统）与具有两个激活剂或两个抑制剂的“冗余”系统（三维系统）的相对稳定性。我们发现复制事件既可以扩展也可以收缩模式空间。我们从从这个空间的随机逃逸时间（也称为“渠化潜力”）的角度研究发育稳健性。我们将模式形成的输出嵌入到一个明确的基因复制、基因丢失以及渠化潜力陡度变化的进化模型中。我们发现，在所有恒定条件下，系统会朝着偏好与低表型变异性和更长寿命相关的陡峭潜力发展。这种偏好导致冗余基因型的密度总体下降，因为发育稳健性抵消了遗传稳健性的优势。
