DNA is the gold standard of identification. Except when it’s not. In rare cases when a person has two complete sets of DNA, that person’s identity may be up in the air. Meanwhile, DNA ancestry tests are proving frustratingly vague: dishing up generalities about where you came from rather than anything specific. And decoding a genome is still relatively expensive and time-consuming. So, while we refine our ability to work with DNA, the search is on for a quick and easy biomarker test to tell us who we are. In this hour: the story of chimeras – people who have two sets of DNA; a reporter whose ancestry tests revealed she is related to Napoleon and Marie Antoinette; and the eyes have it in Somaliland, the first nation to use iris scans in an election. Find out why your irises may be what ultimately distinguishes you from the crowd.Guests: Tina Hesman Saey – Senior writer covering molecular biology for Science News, including a series on genetic testing. Carl Zimmer – Columnist for The New York Times, author of, “She Has Her Mother’s Laugh: The Powers, Perversions, and Potential of Heredity.” Kevin Bowyer – Professor of computer science and engineering, University of Notre Dame.  Originally aired July 23, 2018 Learn more about your ad choices. Visit megaphone.fm/adchoices