Question: What do you mean by 'beautiful structures' when talking about viruses? Surely they're bad?

Ian Hands-Portman answered on 11 Mar 2014:

Some viruses are truly and horribly bad – smallpox, ebola and things cause horrific diseases but not all viruses do. When I say they’re beautiful, the shape of them, how they fit themselves together and how they interact with a cell shows a stunning level of detail –

Not my work but there’s a cold virus – I reckon it’s quite a stunning piece of nature

http://www.virology.wisc.edu/virusworld/movies/r14MGS-1.MPG

As for bad, viruses basically drive evolution – they often leave bits of their genes lying around in cells that get used for other things – some estimates say about half of our genes came from viruses originally. There are also viruses that infect bacteria – in fact most of the viruses on Earth are ones that infect bacteria – we call them bacteriophages – they could come in very handy for treating infections in people