Which came first, bacteria or viruses?

Viruses did not evolve first, they found. Instead, viruses and bacteria both descended from an ancient cellular life form. But while – like humans – bacteria evolved to become more complex, viruses became simpler. Today, viruses are so small and simple, they can't even replicate on their own. read more

The “virus-first” hypothesis suggests that viruses evolved before, or at the same time as the first cells. The escape and the regression hypotheses have many more proponents, and more evidence in their favor, than the virus-first hypothesis. read more

Viruses did not evolve first, they found. Instead, viruses and bacteria both descended from an ancient cellular life form. But while – like humans – bacteria evolved to become more complex, viruses became simpler. Today, viruses are so small and simple, they can’t even replicate on their own. read more

Viruses and bacteria have evolved along side of each other for as long as time can tell. There is no way to date or sample bacteria or viruses in a time sensitive way. Some bacteria may have complimented the dependancy of viruses (explaning the complex pathogen which digests bacteria), but my personal understanding is that they were both present when biological life forms first existed. read more