When French scientists Jean-Michel Claverie and Chantal Abergel learned that plants had been revived from 30,000 year old seeds found in squirrel hoards buried deep in the Siberian permafrost, they requested frost samples from the Russian team. They then tempted the samples with fresh amoeba, and were able to lure dormant viruses hiding in the frost into action. The viruses attacked the amoeba, bent them to their will, and started using them as replication laboratories.
When the scientists investigated, they discovered that, on the microscopic scale, the viruses were absolutely enormous. Over a micrometre in size, they are as large as many bacteria, even larger than some of the smallest known free-living eukaryotic cells, and are readily visible using standard microscopes. (The scientists named the virus Pithovirus sibericum because its shape resembled the ancient Greek wine jars called "pithos.")
Fortunately, it appears that the primary threat that this zombie virus poses is to the microscopic amoeba population. Nevertheless, the scientists have also discovered other large viruses, including Pandora viruses and the "microbe mimicking" virus, or Mimivirus. Although the pathology of these viruses is as yet unknown, antibodies to giant viruses have been detected in humans – which means giant viruses can make us their hosts.
The genetic material of these viruses is unusual and overlaps known lifeforms to a very limited degree, which has the scientific community very intrigued about the possibilities for new discoveries. But only time will tell what else is lurking deep under the frost, waiting to be brought back from the dead...
