Posted on Thursday 13 May 2004 to Frontiers

Viruses share a common ancestor that existed over 3 billion years ago and may even have even preceded cellular forms of life. Researchers at Montana State University have come to this conclusion after comparing the protein coating of an exotic virus strain, recently isolated from a hot spring at Yellowstone National Park, with a range of vastly different virus types. Unlike most viruses, this new virus doesn't reproduce by infecting living cells but through a chemical reaction and yet it has been found to share a common protein structure with the other viruses. Furthermore, these proteins have shown no significant similarities with the proteins of living cells and this suggests that viruses must have split off from other forms of life very early on. There are even wilder possibilities: that viruses may have preceded cellular life on Earth or even arrived here from outer space.