Skip to Content

Comic Explodes the “DNA Is Just Source Code” Metaphor

Sorry, smug technophiles, biology is a lot messier than even the most poorly optimized code.
November 19, 2015

Randall Munroe, the polymath behind popular webcomic XKCD, is here with a reality check for everyone (myself emphatically included) guilty of trumping up the biotech revolution.

You know the rhetoric—DNA is just the alphabet of life, genes are just words, and now that we’ve figured out the language it’s time to start writing the next great biological novel! Or, if zeroes and ones are more your speed: “DNA is the source code.” So says Munroe’s stand-in for the slightly smug technophile who is sure “biology is largely solved” and that we can just read and rewrite it like any other coding language. Not so fast.

For folks who, like me, are coding neophytes, let’s elaborate a bit on the point about optimization; let’s go back to the literature metaphors. Think of DNA as a constantly edited manuscript. The vast majority of evolution is limited to working from the same document it started with. It can add to it, cross things out, rearrange the pieces, scribble notes in the margins, but there is no “undo” button. (To be fair, every now and then, mutation will introduce bits of totally fresh material—but it’s a total crapshoot. Like a cat periodically trotting across the keyboard.)

Imagine an MS Word document billions of pages long, edited by billions of different people over billions of years, and every single one of them had to leave track changes on. It’d make House of Leaves look like See Spot Run.

When faced with the messiness of real DNA, metaphors comparing genetics to a language (coding or literary) might be a bit too tidy. As my friend and former MIT Technology Review special projects editor Stephen Cass put it on Facebook: “Next time you read breathless headlines about how we’re (once again) on the cusp of a biotech revolution, think of today’s XKCD.”

In the breakneck world of biotech reporting, a bit of breath-catching never hurt anyone.

Keep Reading

Most Popular

A Roomba recorded a woman on the toilet. How did screenshots end up on Facebook?

Robot vacuum companies say your images are safe, but a sprawling global supply chain for data from our devices creates risk.

A startup says it’s begun releasing particles into the atmosphere, in an effort to tweak the climate

Make Sunsets is already attempting to earn revenue for geoengineering, a move likely to provoke widespread criticism.

10 Breakthrough Technologies 2023

Every year, we pick the 10 technologies that matter the most right now. We look for advances that will have a big impact on our lives and break down why they matter.

These exclusive satellite images show that Saudi Arabia’s sci-fi megacity is well underway

Weirdly, any recent work on The Line doesn’t show up on Google Maps. But we got the images anyway.

Stay connected

Illustration by Rose Wong

Get the latest updates from
MIT Technology Review

Discover special offers, top stories, upcoming events, and more.

Thank you for submitting your email!

Explore more newsletters

It looks like something went wrong.

We’re having trouble saving your preferences. Try refreshing this page and updating them one more time. If you continue to get this message, reach out to us at customer-service@technologyreview.com with a list of newsletters you’d like to receive.