The term molecular clock refers to the use of DNA or other molecular data to estimate the time of evolutionary divergence between species. There are several synonyms for the term that are commonly used in scientific literature. These include molecular dating, phylogenetic clock, and evolutionary rate. Molecular dating, as the name suggests, refers to the use of molecular data to determine the timing of evolutionary events. The term phylogenetic clock emphasizes the use of molecular data to reconstruct evolutionary relationships between species, while the term evolutionary rate refers to the speed at which evolution occurs, as estimated from molecular data. Regardless of the specific term used, the molecular clock is an important tool for understanding the history of life on Earth.