Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI.
Mol Biol Evol. 2018 Jun 1;35(6):1327-1331. doi: 10.1093/molbev/msy065.
Although the neutral theory of molecular evolution was proposed to explain DNA and protein sequence evolution, in principle it could also explain phenotypic evolution. Nevertheless, overall, phenotypes should be less likely than genotypes to evolve neutrally. I propose that, when phenotypic traits are stratified according to a hierarchy of biological organization, the fraction of evolutionary changes in phenotype that are adaptive rises with the phenotypic level considered. Consistently, molecular traits are frequently found to evolve neutrally whereas a large, random set of organismal traits were recently reported to vary largely adaptively. Many more studies of unbiased samples of phenotypic traits are needed to test the general validity of this hypothesis.
尽管分子进化的中性理论被提出是为了解释 DNA 和蛋白质序列的进化,但从理论上讲,它也可以解释表型进化。然而,总体而言,表型应该比基因型更不可能以中性方式进化。我提出,当根据生物组织层次结构对表型特征进行分层时,考虑到的表型水平越高,表型进化的适应性变化比例就越高。一致地,分子特征经常被发现以中性方式进化,而最近报道的大量随机生物体特征也有很大的适应性变化。需要更多的、无偏的表型特征样本研究来检验这一假说的普遍有效性。