Hunt for the Oldest DNA tells the story of a maverick gene hunter, whose single-minded pursuit of an improbable scientific vision would tease and torment him before ending with a stunning triumph: a lost world recovered from a spoonful of dirt.

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 with a landmark breakthrough–with massive implications for how we understand the deep past.

After many years of failure, Willerslev 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. Signaling a new era in DNA 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.