mutation

Imagine a set of instructions being copied again and again. Most of the time, the copy stays the same, but once in a while, one small part changes. That is the basic idea behind a mutation. In biology, it means a change in the DNA of a living thing. Sometimes that change has no clear effect. Sometimes it is harmful, and sometimes it helps.

The word is used most often in science and medicine. You might read about a virus developing a new mutation, or a plant showing a genetic change that affects its color or shape. Outside science, the word can also describe a changed form of something, but that use is less common.

A mutation is a change in the genetic material of a living thing, usually in its DNA. The change can be very small, affecting just one part of the DNA code, or larger, involving a bigger section of genetic material. Mutations can happen naturally when cells copy DNA, and they can also be caused by outside factors such as radiation, chemicals, or viruses.

In biology, mutations matter because they create variation. Many have little or no noticeable effect. Some cause problems, including disease or poor development. Others can give a living thing an advantage, which is one reason mutations are important in evolution. Over long periods of time, useful genetic changes can spread through a group as living things pass them on to the next generation.

The word also appears outside biology, though less often. In those cases, it usually means a new or altered form that has grown out of an older one. For example, a writer might describe a later version of an idea as a mutation of the original. This use keeps the sense of change, but the scientific meaning is still the main one.

Think of it as a change that appears during copying or development and leads to something a bit different from before. In everyday English, the word strongly suggests genetics, science, and the way living things can change over time.