to randomly change a setting in the hard drive of a computer, the result would be harmful rather than helpful. Every once in a while, however, a mutation gives an organism a certain advantage over other individuals. For example, webbed toes allow for faster swimming. Similarly,thicker coats allow for being able to live in cold temperatures. These changes help an organism live. The trait is then passed on to its offspring. These offspring are more likely to survive and produce other offspring that will also live. Thus, through mutations a species can develop characteristics that allow it to live in different environments. Scientists believe that most mutation are caused by mistakes in the DNA replication during reproduction or development. Mutation can also be a result of exposure to things in the environment. These are called mutagens. Some mutagens occur naturally. Ultraviolet radiation form the sun, for example, can damage DNA.