Fun With DNA
Tiny computers, microscopic art, bringing back the dodo—the future uses of the double helix
In the past couple of decades, genetics has revolutionized fields such as agriculture, criminal justice, and—of course—medicine. In the next couple, expect DNA to turn up in such far-flung disciplines as archaeology, fine arts, and computing. The DNA molecule is capable of storing vast amounts of data and is remarkably resistant to deterioration—it can survive for thousands of years—and we’ve only just begun to explore its many possible applications. Here are some of the ways it might be put to use in the future.
1 | Foiling Disguises and Bringing Back Neanderthals
Because genes strongly influence hair color, eye color, and facial structure, you can get a rough idea of what a person looks like by trawling through his or her DNA. That information could prove useful to police departments, among other organizations. Miami police have been searching for several years for the so-called Creeper, who breaks into women’s homes at night. The Creeper always covers his face, but scientists recently extracted DNA from samples collected at crime scenes in order to create a facial composite for a wanted poster. Such work is far from perfect—it can’t produce portrait-quality images. But it can help nail down certain features, and it sidesteps problems (such as bias and faulty memory) associated with eyewitness accounts.
This facial-profiling technology could help archaeologists, too. No contemporary portraits survive of the notorious English monarch Richard III, for instance, and many later depictions show him with dark hair and steel-colored eyes. But by analyzing DNA from his corpse (recently discovered under a parking lot in central England), scientists were able to determine that there is a 96 percent chance he had blue eyes and a 77 percent chance he had blond hair. Based on similar research, scientists concluded that some Neanderthals probably had reddish hair and fair skin.
In more outré work, geneticists could resurrect woolly mammoths, dodos, and other extinct species by extracting DNA from remains, sequencing it, and injecting copies into the egg cells of related species—using an elephant egg and womb to gestate a woolly mammoth, for instance. In theory, scientists could even resurrect one of those redheaded Neanderthals, using a human surrogate. Bringing back dinosaurs would be vastly more difficult, however: Because they died out 65 million years ago, their DNA has degraded into tatters.
2 | Authenticating Sushi … and Picassos
A recent study of the seafood industry by Oceana, a conservation group, found that, nationwide, grocery stores mislabeled nearly one-fifth of all the fish they sold. Sushi restaurants were even worse, serving a fish other than what was promised on the menu three-quarters of the time. Simple confusion might explain some of the discrepancies, since fish species can be hard to tell apart. But some merchants seemed to deliberately substitute cheap fish like tilapia for more expensive fare.
DNA bar coding can help uncover such practices. By extracting a bit of muscle from a fish and sequencing the DNA inside, scientists can quickly tell one species from another. Bar-coding technology is accessible enough that high-school students have used it to expose fraud at restaurants, and if the technology continues to evolve, consumers could someday bring handheld bar coders to the table, to see for themselves whether they’re really getting the bluefin tuna they ordered.
DNA could be used to expose fraud in the art world, too. Billions of dollars’ worth of art changes hands every year, and some experts estimate that 40 percent of it is fake. Professional authentication can help, but recent scandals involving works said to have been painted by Jackson Pollock, Amedeo Modigliani, and others have shown that a skillful forger can fool even the most respected experts. To combat this problem, some scientists have suggested attaching a small plastic label full of DNA to works of art. Rather than using the artist’s own DNA—which a thief could lift from clothes, trash, or stray hairs—these labels would contain strands of DNA from another creature, with snippets of synthetic DNA woven in. To authenticate the piece, scientists would extract DNA from the label, sequence the synthetic bits, and consult an encrypted database. Only if the sequence matched the database record would the piece be pronounced genuine.
3 | Spinning Gold and Locking Up Viruses
DNA itself has become a trendy artistic medium. The DNA inside cells consists of long strings of chemical “letters” (A, C, G, and T), and several scientists have written computer programs that can translate those strings into sequences of musical notes—literal songs of ourselves. Artists have also begun to produce visual or conceptual works by manipulating creatures’ genes—for example, painting fluorescent beach scenes using genetically modified bacteria that glow when exposed to light. Researchers at Harvard and in Japan genetically engineered silkworms to spin threads laced with actual gold, à la Rumpelstiltskin. Some of the same researchers also plan to encode every article on Wikipedia into synthetic strings of DNA letters, then weave that DNA into the natural genome of apples—a nod to the fruit of knowledge from the Garden of Eden.
Scientists have experimented with a technology that allows them to make DNA “origami”: Because strands of DNA stick together in precise ways (the DNA letter A always bonds to a T, for example), they can design snippets of DNA that will seek one another out and bind together in complicated shapes. So far, scientists have mostly doodled with this technology, making microscopic stars, smiley faces, and other images. But DNA origami could prove useful in medicine someday. Specially crafted DNA-origami lockboxes could be used to deliver drugs directly to a tumor. The lockboxes would open only after binding with targeted tumor cells. Similarly, DNA cages could act as jails for viruses and spirit them away for destruction.
4 | Preserving Old Movies and Predicting the Weather
DNA is the oldest medium in existence for storing data, so it makes sense that the double helix could find use in computing. Scientists can encode data as DNA by assigning every number and letter to a unique string of A’s, C’s, G’s, and T’s (much like modern computers encode data as 1’s and 0’s) and then producing strands of synthetic DNA with that information. DNA-sequencing machines can later extract the data.
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Why bother? Aside from being ultra-durable, DNA is also an incredibly efficient way to store information. Scientists have already been able to fit 700 terabytes of data—roughly the equivalent of 1 million CDs—in a single gram of DNA, and it can theoretically hold far more. By some estimates, all of the data currently stored on the world’s disk drives could fit in the palm of your hand if encoded in DNA. For this reason, Technicolor, the entertainment company, has begun storing old movies as DNA, starting with the 1902 film A Trip to the Moon. You can also copy DNA-based data nearly indefinitely with simple enzymes. The Harvard geneticist George Church recently converted a book he wrote into DNA, then made 70 billion copies in a test tube—making it the most reproduced text in history.
Beyond just storing data, some researchers have suggested using DNA to build biological computers. These biocomputers wouldn’t look like laptops, with screens and keyboards. Rather, they’d be chemicals inside test tubes or biological membranes. But like laptops, they would have the ability to take in information, process it, and act. DNA seems especially promising for parallel processing, which involves making millions or even billions of computations simultaneously. (An example is weather forecasting, which involves integrating temperature, barometric pressure, and humidity data for many, many points on the Earth’s surface all at once.) And unlike electronic devices, which can’t easily infiltrate living cells, DNA-based computers could penetrate these spaces, giving us ways to record information and possibly fight disease in real time.
Church notes that above all, DNA holds great promise for data encoding because the medium won’t ever grow obsolete. “We lose our affection for floppy drives” and other technologies, Church says. “But we’ll always have some interest in DNA.”