The triceratops scene from Jurassic Park, with a tear added to the dinosaur's faceI have news that’s incredibly disappointing to my younger self, age 3 to 9. Sadly, we’ll never be able to build a real-life Jurassic Park, because the half-life of DNA strands only lasts 521 years.

While it’s been generally assumed that DNA would break down after a long enough period, proving it would require large samples of theoretically DNA-rich material. A group of Australian scientists found the right test materials in bones of the now-extinct moa, an emu-like bird  from New Zealand that looked a little something like this:

The extinct bird, the moa

These bones were hundreds or thousands of years old, not millions, but it gave the scientists enough information to conclude that it takes 521 years after cell death for the bonds that hold together DNA to dissolve completely. Even under perfect conditions (for example, protected inside mosquitos preserved in amber like in Crichton’s book and Spielberg’s movie), there is no way the DNA would remain intact after the 6.8 million years that separate us from dinosaurs. The team’s best estimate for the oldest potentially readable DNA under perfect conditions is 1.5 million.

So no Cloneosaurus in our future. Though with that 521 year half-life bearing down on us, we still might be able to make a cloned Christopher Columbus if we hurry.