The mutation rate refers to the frequency at which changes, or mutations, occur in the DNA sequence of an organism. These changes can happen due to various factors, including errors during DNA replication or exposure to environmental influences like radiation. The mutation rate can vary significantly among different species and even among different genes within the same organism. Understanding mutation rates is crucial in fields like genetics and evolutionary biology, as they can influence genetic diversity and adaptation. High mutation rates may lead to rapid evolution, while low rates can result in more stable genetic traits. Researchers study mutation rates to gain insights into processes like evolution and disease development.