Mamie Underhill (L), 104, and her daughter Leita Chapman attend a birthday celebration for five women residents at the Solheim Lutheran Home who are 100-years-old or more August 16, 2002. (Getty Images)
(CNN) – Scientists are getting closer to unlocking one of the world's biggest genetic mysteries: Why do some people live so much longer than others? The latest research is coming from a team at Boston University. Dr. Thomas Perls, associate professor of medicine and geriatrics at BU's School of Medicine, joined us on Tuesday's American Morning to discuss the secrets to being a centenarian. Watch 