Elizabeth Blackburn, working with Joseph Gall at Yale University is generally credited with discovering the unusual nature of telomeres that function like caps at the ends of chromosomes. Their work was published in 1978. Blackburn, Greider, and Szostak received the Nobel Prize in Physiology or Medicine, 2009, for discovering how chromosomes are protected by telomeres and how Telomerase can help protect the telomeres—help keep them longer. (In some types of cancers, telomerase is hyperactive.) If you are interested in telomeres, you may want to listen to a 2008 YouTube presentation that was recorded by Blackburn talking about aging and telomeres. More tomorrow.