Chapter 17, Problem 13A

Summary Introduction

To determine:

The meaning of the colored bands in the given figure represents.

Introduction:

A molecular clock is a model that is used to compare DNA sequences from two difference species to estimate how long species have been evolving since they diverged from common ancestor.

Answer to Problem 13A

The color bands in the given diagram represents mutations.

Explanation of Solution

Molecular clocks are used to compare the DNA sequences or amino-acid sequences of genes that are shared by different species. The differences between the genes indicates the presence of mutations.The more mutations that have accumulated, the more time have been passed since divergence. So, these mutations help to determine the degree of relationships among species.

Although, the rate of mutation is affected by many factors, including the type of mutation, where it is in the genome, the type of protein that the mutation affects and the population in which mutation occurs and this makes molecular clocks difficult to read yet molecular clocks are considered valuable tools for determining a relative time of divergence of a species.