Proteins approximately behave as molecular clocks, accumulating amino acid replacements at a more or less constant rate. Nonetheless, each protein displays a characteristic rate of evolution: whereas some proteins remain largely unaltered over large periods of time, others can rapidly accumulate amino acid replacements. An article by Richard Dickerson, published in the first issue of the Journal of Molecular Evolution (J Mol Evol 1:26–45, 1971), described the first analysis in which the rates of evolution of many proteins were compared, and the differences were interpreted in the light of their function. When comparing the sequences of fibrinopeptides, hemoglobin, and cytochrome c of different species, he observed a linear relationship between the number of amino acid replacements and divergence time. Remarkably, fibrinopeptides had evolved fast, cytochrome c had evolved slowly, and hemoglobin exhibited an intermediate rate of evolution. As the Journal of Molecular Evolution celebrates its 50th anniversary, I highlight this landmark article and reflect on its impact on the field of Molecular Evolution.

蛋白质大致表现为分子钟，以或多或少的恒定速率积累氨基酸替代物。尽管如此，每种蛋白质都表现出特征性的进化速度：虽然一些蛋白质在很长一段时间内基本保持不变，但其他蛋白质可以迅速积累氨基酸替代物。理查德·迪克森 (Richard Dickerson) 发表在第一期分子进化杂志(J Mol Evol 1:26–45, 1971) 上的一篇文章描述了对许多蛋白质的进化速率进行比较的第一次分析，差异是根据它们的功能来解释。比较纤维蛋白肽、血红蛋白和细胞色素c的序列时对于不同的物种，他观察到氨基酸替换的数量和发散时间之间的线性关系。值得注意的是，纤维蛋白肽的进化速度很快，细胞色素c 的进化速度很慢，而血红蛋白则表现出中等的进化速度。在《分子进化杂志》庆祝其成立 50 周年之际，我重点介绍了这篇具有里程碑意义的文章，并反思了它对分子进化领域的影响。