"Last year, researchers at University College London's Institute of Healthy Ageing were looking through their microscopes when they saw something amazing."

"David Gems, professor of biogerentology, was part of the team looking for answers to big questions about human aging in small, squishy little creatures nearing the end of their lives. Their official name: Caenorhabditis elegans. You and I know them as worms. As they neared the end of their life, the tiny worms moved more and more slowly."

"Suddenly there appears a sort of ghostly blue fluorescence," Gems tells Jacki Lyden, host of weekends on All Things Considered. "And then it spreads in a kind of flashing wave from the front end to the back end. ... It's really quite a sort of eerie phenomenon because it's reminiscent of the soul departing the worm."