Smithsonian/Roshan Patel It started, as many cancers do, with a lump. Keepers at the Smithsonian’s National Zoo’s Reptile Discovery Center spotted it during a routine checkup—a small ...

Apes do live artificially long in captivity." The beauty of the Doppler machine, National Zoo primates curator Lisa Stevens tells me, is that you can literally watch and videotape the heart at work.