Definition of molecular clock in US English:

molecular clock


  • The average rate at which a species' genome accumulates mutations, used to measure their evolutionary divergence and in other calculations.

    • ‘Here, we discuss the usefulness and limitations of molecular clocks in studying avian evolution, with emphasis on the use of an accurate calibration point.’
    • ‘We introduce a parametric model that relaxes the molecular clock by allowing rates to vary across lineages according to a compound Poisson process.’
    • ‘Before we can draw inferences from a molecular clock, we must calibrate its ‘ticking rate.’’
    • ‘Divergence times of living species, estimated from molecular clocks, have the potential to constrain hypotheses of the relationships of fossil species.’
    • ‘The majority of the fossils used for calibration of avian molecular clocks have uncertain phylogenetic relationships.’