Antibiotic resistance is ancient

Antibiotic resistance is thought to have evolved long before naturally occurring antibiotics and their derivatives were used to treat human disease, but direct evidence for genes that encode resistance has been lacking. Now, an ancient vancomycin-resistance gene has been recovered from 30,000-year-old samples of Siberian permafrost, and the three-dimensional structure of its product has been compared with that of its modern counterpart. There are minor structural differences between the ancient and modern versions, but the differences are not reflected in enzyme function.