Question: What would happen if there were no viruses in the world?

Ian Hands-Portman answered on 13 Mar 2014:

We’d be up to our necks in bacteria!

Just looking at the sea, at least 70% of bacteria are infected with a virus and something like 20% of bacteria are killed every single day by a virus.

They also help swap genes around between different species, this has its down sides because it allows antibiotic resistance to spread but the genes that allow our cells to stick together and the genes that allow mothers to make a placenta originally came from viruses. Estimates vary but at least half our genes came to us via viruses – they might make us ill but without them we’d still be a puddle of slime.