Fontana W, Schuster P
Institut für Theoretische Chemie, Universität Wien, Währingerstrasse 17, A-1090 Wien, Austria.
Science. 1998 May 29;280(5368):1451-5. doi: 10.1126/science.280.5368.1451.
To distinguish continuous from discontinuous evolutionary change, a relation of nearness between phenotypes is needed. Such a relation is based on the probability of one phenotype being accessible from another through changes in the genotype. This nearness relation is exemplified by calculating the shape neighborhood of a transfer RNA secondary structure and provides a characterization of discontinuous shape transformations in RNA. The simulation of replicating and mutating RNA populations under selection shows that sudden adaptive progress coincides mostly, but not always, with discontinuous shape transformations. The nature of these transformations illuminates the key role of neutral genetic drift in their realization.
为了区分连续进化变化和不连续进化变化，需要一种表型之间的接近关系。这种关系基于一种表型通过基因型变化从另一种表型可达的概率。这种接近关系通过计算转运RNA二级结构的形状邻域得到例证，并提供了RNA中不连续形状转变的一种特征描述。在选择作用下对RNA群体进行复制和突变的模拟表明，突然的适应性进展大多（但并非总是）与不连续形状转变相一致。这些转变 的本质揭示了中性遗传漂变在其实现过程中的关键作用。
