The Galapagos Islands' giant tortoises are one of the world's best examples of evolution. Scientists are pioneering new conservation strategies to save them from extinction and restore their habitat.
Is an extinct animal really gone forever?
When 100-year-old giant tortoise Lonesome George died in 2012, the world thought his species was lost forever. We went to the Galápagos Islands looking for 'extinct' tortoises – and we found them.
Their flimsy chances rely on the eggs and sperm from the remaining three elderly animals, combined with frozen DNA from dead rhino.