用数字化生物演义适者生存原理(转自<Nature>)    

【将进酒】 于 07/24/01 15:41:06 加贴在 闪亮的日子 ：

用数字化生物演义适者生存原理数字化生物实质上是遵守突变和自然选择原理的计算机程序，可用于研究演化的基本过程之间的相互作用。科学家所做的这样一个实验，为达尔文关于具有高复制率的基因型适于存活的概念(即“适者生存”的概念)赋予了新的含义。例如，实验表明，一个具有非常高的复制率(是对方的12倍)的数字化生物竞争不过复制较慢的生物。成功的生物占据较低的适应峰，但却位于适应表面的平坦区。用概率论中的说法就是，这些生物缺乏适应性的弱点被它们从其突变邻居处得到的支持远远补偿了。

详见2001年7月19日出版的<自然>杂志。网络版不提供全文，原文摘要如下：

           Evolution of digital organisms at high mutation rates
           leads to survival of the flattest

           Claus O. Wilke, Jia Lan Wang, Charles Ofria, Richard E. Lenski and
           Christoph Adami

           Darwinian evolution favours genotypes with high replication rates, a
           process called `survival of the fittest'. However, knowing the replication
           rate of each individual genotype may not suffice to predict the eventual
           survivor, even in an asexual population. According to quasi-species theory,
           selection favours the cloud of genotypes, interconnected by mutation,
           whose average replication rate is highest. Here we confirm this prediction
           using digital organisms that self-replicate, mutate and evolve. Forty pairs
           of populations were derived from 40 different ancestors in identical
           selective environments, except that one of each pair experienced a 4-fold
           higher mutation rate. In 12 cases, the dominant genotype that evolved at
           the lower mutation rate achieved a replication rate 1.5-fold faster than its
           counterpart. We allowed each of these disparate pairs to compete across a
           range of mutation rates. In each case, as mutation rate was increased, the
           outcome of competition switched to favour the genotype with the lower
           replication rate. These genotypes, although they occupied lower fitness
           peaks, were located in flatter regions of the fitness surface and were
           therefore more robust with respect to mutations.

更多详情见作者所在的Digital Life Laboratory, CIT的主页

http://www.dllab.caltech.edu/

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