In his book, The Mutant Project: Inside the Global Race to Genetically Modify Humans, the scholar Eben Kirksey explains how metaphors like gene editing, which suggest precision, in reality hide messy cellular dynamics. Kirksey says an armed drone attack gives a more accurate comparison. He writes:

“Gene ‘editing’ is not a particularly good metaphor for explaining the science of CRISPR. With the computer I can easily cut and paste text from one application to another, or make clean deletions – letter by letter, line by line. But CRISPR does not have these precise editorial functions. CRISPR is more like a tiny reaper drone that can produce targeted damage to DNA. Sometimes it makes a precision, missile strike, destroying the target. It can also produce serious collateral damage, like a drone attack that accidentally takes out a wedding party instead of the intended target. Scientists often accidentally blast away big chunks of DNA as they try to improve the code of life. CRISPR can also go astray when the pre-programmed coordinates are ambiguous, like a rogue drone that automatically strikes the friends, neighbours, and relatives of a suspected terrorist. CRISPR can persist in cells for weeks, bouncing around the chromosomes, producing damage to DNA over and over again, every time it finds a near match to the intended target.

“It is important to signal a sense of risk or need for caution in using CRISPR. Other metaphors – like genetic ‘surgery’ or DNA ‘hacking’ – have been proposed to replace the idea of ‘editing’. The idea of genetic surgery suggests that there can be a slip of the surgeon's knife, creating an unintended injury. Each of these images – the targeted missile, the surgeon's scalpel, the hacker’s code – offers a perspective on how CRISPR works, even while concealing messy cellular dynamics. In the absence of a perfect metaphor, ultimately, I think the technical language describes it best: CRISPR is an enzyme that produces targeted mutagenesis.

“In other words, CRISPR generates mutants.”