Question

Divergence time estimates based on molecular clocks are

A. likely to be correct plus or minus a few decades.
B. more reliable than divergence dates that are based on analysis of the fossil record.
C. best interpreted with caution, since they depend on assumptions that are difficult to test.
D. usually worthless since we cannot directly observe divergence times unless we invent a time machine.

Answer 1

Divergence time estimations based on molecular clocks should be approached with caution as they rely on the assumption of a steady mutation rate, which can be variable.The correct option is C.

Step-by-step explanation:

Divergence time estimates based on molecular clocks are C. best interpreted with caution, since they depend on assumptions that are difficult to test.

A molecular clock uses DNA or protein differences to measure how long it has been since related species diverged from a common ancestor. The concept of the molecular clock is based on the assumption that mutations accumulate at a steady average rate.

However, recent studies and debates in the field of paleogenetics suggest that this rate of mutation may be variable and influenced by different factors and that the genetic change occurs for various reasons at various rates.

Therefore, while molecular clocks can provide estimations and a useful tool for comparing divergence times, scientists must use these tools with caution and in conjunction with other forms of evidence such as the fossil record and geological data.The correct option is C.