Here's a theory for a comedian to consider: dinosaurs done-in by avian flu. Silly as that may be, we imagine that viruses have been infecting organisms since life first appeared on Earth, but this is mostly just a hunch. New research is studying whether special environments (not related to dinosaurs) could potentially preserve vestiges of ancient viruses.
A census of all the current living organisms would show that viruses outnumber everything else 10 to one. Whether this was true long ago is uncertain.
"There is no known evidence of viruses in the rock record," says Jennifer Kyle, a postdoctoral fellow at NASA Ames Research Center and Portland State University. "Due to their small size and lack of a metabolism, many scientists assume that [viruses] would not be preserved."
However, viruses have distinct morphologies and chemistries that could be distinguished from those of their hosts. The trouble is where to search for these viral remnants.
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