When sequencing 400,00 pieces of viral DNA located in Lassen Volcanic National Park he found a gene (made from DNA) that looked like the gene for a protein coat from an RNA virus. Upon further sequencing they found a a gene for DNA replication typical of a DNA virus. This was significant as the prevalent theory is that the prebiotic world was composed of RNA. The find proves that modern viruses can combine information coded in the two normally separate genetic molecules. This lends support to the idea that it was viruses that performed the “upgrade” from RNA and effectively gave rise to DNA (and all life as we know it today).
Stedman suggests that it may have formed when an RNA virus, DNA virus and retrovirus all infected a cell at the same time. This perfect viral storm could have triggered a three way genetic mash-up.
via New Scientist [link]