Could it ever, even theoretically, exist? A Russian scientist named Dr. Anatoli Brouchkov believes it's out there, and he thinks he found it in 3.5-million-year-old viru.

. Scientists who study glacier ice have found viruses nearly 15,000 years old in two ice samples taken from the Tibetan Plateau in China. Most of those viruses, which survived because they had remained frozen, are unlike any viruses that have been cataloged to date.