[thedoc (OP)]

Simon, Hastings asked the Naked Scientists:
   
Have any viruses that are potentially lethal to their host ever been so successful  i.e. reproduced so prolifically that they have caused the extinction of their host? And if so, is this not detrimental to the virus as it would no longer have a host to survive in?

Dr Karl partly answered it by saying that evolution doesn't have to be perfect, just good enough. I suppose it is more a question about evolution if a virus is deadly it just seems like it's cutting its nose off to spite its face. But it's hard to remember that viruses aren't willful and don't often respond to proverbs!

Any answer would be much appreciated.

Simon from Hastings

What do you think?

[evan_au]

Ebola has a fairly rapid progress which becomes visible to surrounding people, which probably reduces the number of people who are infected by each victim.

There is a hypothesis that over time, a virus which has been circulating in animals, and is newly exposed to humans would eventually become less lethal. In so doing, the number of infected individuals would actually increase.

[CliffordK]

It is not really a virus, but the Tasmanian Devil is at risk of extinction from a type of communicable cancer known as facial tumor disease.