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 warning, joins Ira to discuss the concept of mirror life and why a group of researchers felt compelled to call for a halt to mirror life experiments.

Transcripts for each segment will be available after the show airs on sciencefriday.com.

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