In the fall of 2019, the world began one of the largest evolutionary biology experiments in modern history. Somewhere near the city of Wuhan in eastern China, a coronavirus acquired the ability to live inside humans rather than the bats and other mammals that had been its hosts. It adapted further to become efficient at spreading from one person to the next, even before the body’s defenses could rise against it. But the evolutionary chess game didn’t stop there, and we have a Greek alphabet soup of SARS-CoV-2 variants to prove it. Researchers around the world are trying to understand the virus’s evolution in more detail, and particularly how mutations…