Plants keep track of the time of the day with a molecular clock.

However, hominins discovered more recently are somewhat older than the molecular clock would suggest.

More likely, the assumptions behind molecular clocks do not hold exactly.

The wide range of dates is due to the different records used to calibrate the molecular clock.

Application of molecular clock allowed to estimate divergence times for these groups.

Without any type of feedback repression, the molecular clock would have a period of just a few hours.

These dates were all calculated using a molecular clock.

A region which mutates at predictable rate is a candidate for use as a molecular clock.

The critics also began wondering just how reliable the molecular clock was.

Researchers often estimate the ages of groups using what are called molecular clocks, as was done in the new study.