Elena S F, Cooper V S, Lenski R E
Center for Microbial Ecology, Michigan State University, East Lansing, 48824, USA.
Science. 1996 Jun 21;272(5269):1802-4. doi: 10.1126/science.272.5269.1802.
For more than two decades there has been intense debate over the hypothesis that most morphological evolution occurs during relatively brief episodes of rapid change that punctuate much longer periods of stasis. A clear and unambiguous case of punctuated evolution is presented for cell size in a population of Escherichia coli evolving for 3000 generations in a constant environment. The punctuation is caused by natural selection as rare, beneficial mutations sweep successively through the population. This experiment shows that the most elementary processes in population genetics can give rise to punctuated evolution dynamics.
二十多年来，对于以下假说一直存在激烈争论：大多数形态演变发生在相对短暂的快速变化阶段，这些阶段打断了长得多的停滞期。本文给出了一个明确无误的间断性进化实例，是关于在恒定环境中历经3000代进化的大肠杆菌群体的细胞大小。这种间断是由自然选择导致的，因为罕见的有益突变相继席卷整个群体。该实验表明，群体遗传学中最基本的过程能够产生间断性进化动态。
