People who have suffered from an autoimmune disorder such as rheumatoid arthritis can attest to the pervasive swelling and agonizing pain that comes with it. And yet, in an odd twist of evolutionary fate, it seems that such an ailment is linked to a biological defense from a lethal threat of the past.
Specifically, researchers have recently learned that the bubonic plague in the Middle Ages might have sparked a gene mutation that spared people from the Black Death, but passed on the risk for immune disorders to their descendants. A 2022 study in Nature identified this gene mutation responsible for protecting people from the plague. The groundbreaking study illuminates how humans can adapt quickly to threats in their environment — but it can come at a price.
