A) How do scientists use molecular clocks to study evolution? B) Explain some assumptions and limitations of the molecular clock concept.

A) Molecular clocks help to measure the number of changes and mutations which accumulate in the gene sequence of different species over a period of time.

B)It is based on the fact that genetic mutations although random, occur at a relatively constant rate. Evolutionary biologists use this information to deduce how species evolve and determine when two species diverged on the evolutionary time line.
It is useful in the study of variations in selective forces.
It also facilitates establishing the dates of phylogenetic events including those not documented by fossils.
The molecular clock technique is an important tool in molecular systematics. It helps to determine the correct scientific classification of organisms by deriving information from molecular genetics.

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