Is it possible that dinosaurs will walk the earth once again? Probably not, but what about species that became extinct much more recently, such as the woolly mammoth and the sabre tooth tiger? With the process of de-extinction, this might actually be possible. De-extinction refers to the process of bringing an extinct species back to life. But how does it work and how will it affect Earth’s stable ecosystems? To discuss this matter with us is Dr Bastien Llamas from the University of Adelaide.