“An analysis of 30,000-year-old bacteria whose DNA has been recovered from the Yukon permafrost shows that they were able to resist antibiotics,” providing “the first direct evidence that antibiotic resistance is a widespread natural phenomenon that preceded the modern medical use of antibiotics,” according to a study in Thursday’s issue of the journal Nature, the New York Times reports.

“Experts had long predicted this on theoretical grounds, but they say the new finding underlines the need to use antibiotics sparingly, given that the genes for antibiotic resistance are ubiquitous and can easily be promoted by antibiotics,” the newspaper writes, adding that the finding “underlines the danger of looking at bacteria from a purely medical perspective. Resistance to antibiotics is a defense that bacteria have developed in an arms race that has gone on for a billion years” (Wade, 8/31).