# 4: Mutation and Variation

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The techniques of genetic analysis discussed in the previous chapters depend on the availability of two or more alleles for a gene of interest. Where do these alleles come from? The short answer is mutation. Humans have an interesting relationship with mutation. From our perspective, mutations can be extraordinarily useful, since mutations are need for evolution to occur.Mutation is also essential for the domestication and improvement of almost all of our food. On the other hand, mutations are the cause of many cancers and other diseases, and can be devastating to individuals. Yet, the vast majority of mutations probably go undetected.In this section, we will examine some of the causes and effects of mutations.

Thumbnail: The difference in appearance between pigmented and white peacocks is due to mutation. (Flickr-ecstaticist-CCANS)

This page titled 4: Mutation and Variation is shared under a CC BY-SA 3.0 license and was authored, remixed, and/or curated by Todd Nickle and Isabelle Barrette-Ng via source content that was edited to the style and standards of the LibreTexts platform; a detailed edit history is available upon request.