This news item from Cornell Research is about: Year after year, new strains of influenza evolve. The past year's immunization becomes useless against the current year's virus, and scientists must create a new flu shot. Then, dangerous viral diseases like severe acute respiratory syndrome (SARS) and Ebola, seemingly appear from out of nowhere. What's going on? How does the flu outpace our ability to contain it? How do previously unknown viruses emerge as pathogenic, able to cause disease in humans and animals?