The DNA of ancient microorganisms frozen in glaciers has the ability to return to life as the glaciers melt. A paper published online this week in the Proceedings of the National Academy of Science by scientists who melted five samples of ice ranging in age from 100,000 to 8 million years old found many microorganisms trapped inside. The younger ice contained more lifeforms, which grew fast when cultured, doubling every couple of days. By contrast, the microorganisms from the oldest ice samples grew slowly, doubling only every 70 days. The researchers calculated a DNA half-life of 1.1 million years in Antarctic ice, and warned that as warming melts the glaciers, the revived DNA could fuel a new wave of bacterial evolution. . . Blimey. Will nature’s cryogenesis be the end of us? JULIA WHITTY
