Scientists may compare similar genes in different species and determine what percentage of base pairs is identical. From this, it is estimated how long ago the two species shared a common ancestor. The validity of this conclusion depends on an important assumption. This assumption is that:
A) mutations occur at a fairly constant rate in all evolutionary lines.
B) genetic drift does not occur.
C) the gene codes for a functional protein.
D) both species belong to the same kingdom.

Question

Quizplus · Accepted Answer

The assumption that mutations occur at a fairly constant rate in all evolutionary lines is crucial for estimating the time since two species shared a common ancestor based on the percentage of identical base pairs in similar genes. This concept, known as the molecular clock hypothesis, allows scientists to use genetic similarities and differences to infer evolutionary timelines.

Scientists May Compare Similar Genes in Different Species and Determine