Image Caption
Since protein-coding genes is divided into codons three bases long, insertions and deletions can alter a gene so that its message is no longer correctly parsed. These changes are called frameshifts.
Image use policy: For non-commercial, educational purposes, this image may be used with a Creative Commons CC BY-NC-SA 4.0 license. Please credit as follows: © University of California Museum of Paleontology, Understanding Evolution, www.understandingevolution.org
See where this image appears on the Understanding Evolution website »
This image is part of a series:

Mutation (1 of 4) Substitution
A substitution is a mutation that exchanges one base for another (i.e., a change in a single "chemical letter" such as switching an A to a G).
Mutation (2 of 4) Insertion
Insertions are mutations in which extra base pairs are inserted into a new place in the genes.