Naked Science Forum

Life Sciences => Cells, Microbes & Viruses => Topic started by: Yasser on 07/08/2009 11:30:03

Title: Does natural selection favour organisms that don't kill hosts?
Post by: Yasser on 07/08/2009 11:30:03

Yasser  asked the Naked Scientists:
   
Dear Naked Scientists,
 
In relation to the H1N1 virus, I was just wondering the following question. If natural selection is to be believed, does that validate the proposal that natural selection favours micro organisms that do not kill their hosts?

And if you take this even further does that mean that natural selection (in general for a variety of species) does not favour the H1N1 virus?
 
Best Regards,
Yasser in Canada

What do you think?

Title: Does natural selection favour organisms that don't kill hosts?
Post by: LeeE on 08/08/2009 17:52:26

Unless there's another vector available to the virus to ensure its continuance, I think, in general, the answer is yes.

Title: Does natural selection favour organisms that don't kill hosts?
Post by: Nizzle on 13/08/2009 14:11:25

It depends on incubation time, infectiousness and lethality.

A virus or bacteria that kills the host after it had ample time to spread will have no disadvantage.

Look at Ebola/Marburg virus vs. HIV.

Ebola/Marburg infections are fast, short incubation time, high lethality. This virus is very rare.

HIV infections are slow, long incubation time, but also high (indirect) lethality. This virus is much more common.