A new study from the University of Michigan suggests that beneficial mutations are more common than previously thought but often fail to spread because environments change too quickly. The research proposes a revised view of molecular evolution.
Researchers led by Jianzhi Zhang examined mutations in yeast and E. coli using deep mutational scanning. They found that more than 1 percent of amino acid changing mutations were beneficial, implying that over 99 percent of substitutions should be adaptive under stable conditions. Yet this rate far exceeds what is observed in nature.
