Hunt for the Oldest DNA

Two decades ago, Eske Willerslev had a radical idea: Could DNA, the fragile chemical code of life, survive intact in frozen sediment for millennia? Fellow scientists called him crazy, but the Danish biologist set out to prove everybody wrong, and his perseverance paid off. After years of failure, Willerslev and his team recovered the genetic traces of a lush forest ecosystem from before the ice age, more than two million years ago. The species identified from their DNA lived during the last hot epoch on Earth, enduring months of unbroken winter darkness in a forest that thrived in present-day northern Greenland.

The breakthrough has massive implications for how we understand the deep past. Signaling a new era in genetic research, scientists can now use DNA to travel back millions of years and piece together vanished ecosystems. Today, they are poised to harvest the genetic secrets of these ancient worlds to help us adapt to our own climate future.