An anonymous reader writes: In the world of microbes, viruses are small — notoriously small. Pithovirus is not. The largest virus ever discovered, pithovirus is more massive than even some bacteria. Most viruses copy themselves by hijacking their host’s molecular machinery. But pithovirus is much more independent, possessing some replication machinery of its own. Pithovirus’s relatively large number of genes also differentiated it from other viruses, which are often genetically simple — the smallest have a mere four genes. Pithovirus has around 500 genes, and some are used for complex tasks such as making proteins and repairing and replicating DNA. “It was so different from what we were taught about viruses,” Abergel said.
The stunning find, first revealed in March, isn’t just expanding scientists’ notions of what a virus can be. It is reframing the debate over the origins of life.
