Final answer:
The molecular clock technique tracks species divergence time using DNA or protein difference rates. It assumes a steady mutation rate and compares DNA sequences to estimate divergence time, often refining estimates with fossil record data.
Step-by-step explanation:
The technique used to track the time of species divergence using molecular change rates is known as the molecular clock. This method involves the use of DNA or protein differences to measure the elapsed time since two species diverged from a common ancestor. The molecular clock is based on the principle that mutations accumulate at a relatively steady rate for a given region of DNA over time. By comparing the DNA sequences or amino acids between species, scientists can estimate the number of differences and infer the time of divergence.
Molecular clocks provide crucial insights into evolutionary biology and are used alongside data from the fossil record to paint a more accurate picture of life's history on Earth. As mutations in DNA occur at a constant average rate, the degree of difference between species' DNA sequences can indicate when their evolutionary paths diverged.
For more accurate estimations, molecular clocks can be refined by analyzing different DNA regions and incorporating data on the geological ages of fossils (relative dating techniques). This approach helps correlate molecular data with historical speciation events and the geologic time scale.