The creation of a “mirrored” organism could “trigger severe ecological disruptions,” according to a 300-page technical report released today. Its authors claim such organisms could quickly spread across the world, fatally infect humans, and “directly drive vulnerable plant and animal species to extinction.” The report accompanies an article in Science, also released today, entitled “Confronting Risks of Mirror Life.”

But what, exactly, is a mirrored organism? To answer that, let's consider how extant life works.

Proteins, sugars, lipids, and nucleic acids — key molecules used by cellular life — are all “chiral,” a term derived from the Greek for “hand.” Just as our hands cannot be perfectly aligned on top of one another regardless of how they are rotated, despite being mirror images, the same is true of chiral molecules. The two mirror images of a chiral molecule are called its enantiomers; they possess the same atoms connected [...]