ENCORE Maybe goodbye isn’t forever. Get ready to mingle with mammoths and gaze upon a ground sloth. Scientists want to give some animals a round-trip ticket back from oblivion. Learn how we might go from scraps of extinct DNA to creating live previously-extinct animals, and the man who claims it’s his mission to repopulate the skies with passenger pigeons.
But even if we have the tools to bring vanished animals back, should we?
Plus, the extinction of our own species: are we engineering the end of humans via our technology?
First released April 29, 2013.