Every species becomes extinct eventually. Some leave descendants that continue the evolutionary proliferation of life that kicked off on this planet over 3.5 billion years ago, but no parent species is immortal. Life on Earth is in continual flux, with new lineages emerging as others die back.

But what if we could resurrect lost species? And even if we developed the technology to do so, are such efforts wise during a time when the same attention and energy could be applied to preventing extant species from slipping away? This Friday, researchers are going to converge at the TEDX DeExtinction symposium, partnered with National Geographic, to discuss the possibilities and pitfalls of reviving species that have been lost over the past