Virus

Once you come to understand how the data of some new infection come about, and the logic of the discussion by VW (see http://vwswong.blogspot.com/2009/05/outbreak.html), it becomes obvious that we should not worry too much about new pathogens.

By the law of evolution, they should evolve to suite the host and kill less frequently. On the other hand, if a new pathogen has an exceptionally high mortality, it should have caught dramatic attraction of our attention and would not last long.

(SARS is, of course, the typical example of the latter scenario.)

The logic is simple. In general, when a virus is highly lethal, anyone become infected would succumb quickly; there is not much chance to spread it around. If there evolves a strain of less pathogenic virus, the infected subject would be less unwell and could therefore get around and show it to everyone.

The inevitable, but less well understood, implication is: We - the host - take part in the evolution.

Do you see the problem here ? Let me tell you tomorrow.