Recently, Christian G. Sprecht, a neurobiologist, wrote an intriguing piece in The Scientist about how scientific citations -- references by one paper to previous ones -- mutate over time. What Sprecht meant by this is that over time, a popular paper, instead of being read and cited directly, gets cited by looking at other citations. This somewhat lazy approach is unfortunately all too common, and if a scientist types it wrong, then suddenly there is a mutated version out there, that other scientists reference, leading to a proliferation of errors. By studying these mutations you can learn about the history of the article that is being cited.
But, of course, such errors are not confined to modern scientific articles. People having been miscopying text for thousands of years. And understanding the errors in these manuscripts is actually quite similar to understanding genetics. This sounds a bit odd. What do handwritten manuscripts, from the medieval period or earlier, have to do with genetics? On the surface, nothing: one is a hard experimental science and the other is a distinguished part of the humanities. However, while those who study each of these fields have very little to do with each other, it turns out that there is a great deal of symmetry. And it mainly comes down to mutation. Scholars who study paleography - the field of research that examines ancient writing - are all-too-well-aware of the mistakes that scribes make when copying a text. These types of errors, which can be used to understand the provenance of a history of a document, are actually nearly identical to the types of errors caused by polymerase enzymes, the proteins responsible for copying DNA strands.