分子钟假说的基本原理及在古生物等学科中的应用

THE BASIC PRINCIPLE AND APPLICATION OF THE MOLECULAR CLOCK HYPOTHESIS

研究各个生物类群的起源时间是生物学、古生物学、地质学的重要研究范畴,然而由于化石记录的不完整性,仅仅通过化石无法准确地提供生物各门类的起源时间,更无法真实地反映各门类直接的演化关系,长期以来科学家们都希望能够找到新的突破口。分子钟假说可以在缺乏化石证据的条件下通过分子数据和统计学方法推算各类群间的分歧时间。文中将对分子钟假说的发展历程、基本原理、研究方法及存在的主要问题进行介绍,并就近期利用分子钟的若干研究示例进行分析,以期能对整个分子钟有个更为全面的论述。

Understanding the divergence times of species is crucially important to biology, palaeobiology and geology. However, due to the deficiency of the fossil records, the use of fossils can not actually provide the divergence time and reflecting the genuine evolution relations of the species becomes more difficult. Scientists have been looking for new approaches. With the molecular data and biostatistics methods, the molecular clock hypothesis is able to calculate divergence time of each group without the proof of fossils. This review provides a general introduction of the molecular clock hypothesis, including the development process, basic theories and methods, and the the main defects. The analysis of recent research examples on the molecular clock hypothesis is also included in the essay, which is helpful to provide a more comprehensive introduction to the molecular clock hypothesis.