Evolution

Researchers studying the DNA copying process in Escherichia coli found that the proteins copying DNA stop frequently in the copying process. During these pauses, mistakes can be made in the copy, which can cause mutations that lead to cancer and other dangerous diseases. Normally, cells can repair the damage and the copying proteins responsible.

E. coli is used as a model organism, giving scientists insight into how basic processes may work in humans.

Picture courtesy of:

http://bioweb.uwlax.edu/bio203/s2008/moder_just/

Sources:

http://www.sciencedaily.com/releases/2013/04/130418104334.htm