Science Friday

You’re probably familiar with the concept of handedness—a glove made for your left hand looks basically like the one for your right hand, but won’t fit—it’s a mirror image. Many of life’s important molecules, including proteins and DNA, are chiral, meaning they can exist in either a left-handed or a right-handed form. But on Earth, nature only uses one version or the other in living organisms. Your proteins, for example, are all the left-handed version, while your DNA is all right-handed.With advances in synthetic biology, it could be possible to build an artificial organism that flips that shape, having right-handed proteins and left-handed DNA. Writing in the journal Science, an international group of researchers recently cautioned against anyone trying to create that sort of so-called mirror life, saying that it poses the threat of “unprecedented and irreversible harm” to human health and global ecosystems.Dr. Drew Endy, a synthetic biology researcher at Stanford University and one of the authors of that w