Are Molecular Clocks Calibrated?

Conclusions. The confounding nature of evolutionary rates and time in divergence dating analyses requires that the molecular clock be calibrated independently using information from the evolutionary timescale.

How is the molecular clock calibrated?

One current method of molecular clock calibration is total evidence dating paired with the fossilized birth-death (FBD) model and a model of morphological evolution. The FBD model is novel in that it allows for “sampled ancestors,” which are fossil taxa that are the direct ancestor of a living taxon or lineage.

Are molecular clocks accurate?

Molecular clocks in general are much more "erratic" than previously thought, and practically useless to keep accurate evolutionary time, the researchers conclude. They attribute this to the vagaries of natural selection, which may at times constrain specific genetic mutations in certain lineages.