Re: Weak Vampires?

Gene Ward Smith <gene@[EMAIL PROTECTED]
>:
> > What's idiotic about a predator whose prey are humans? 
> > 
> 
>  The situation cannot arise as a result of evolution. 

Predators change prey as available niches change.

>  Human prey are a very 
>  difficult target, and until the rise of civilizations, were too few to 
>  allow a population of specialized predators anyway. 

Not really. it all depends on what the requirements are of the predator
relative to the prey population. If the prey population can sup****t a
breeding population of the predator (i.e. you are more likley to find
them in China than on Easter Island) then there is no reason they could
not appear. 

Assume that the net annual productivity of a human population is P(h).
Assume that one vampire needs N humans annualy to sustain itself. Assume
that the minimal stable breeding vampire population is Pmin(v). Then we
can easilly calculate the size of human population that will sup****t a
stable vampire population.

There is a buttload of animals that food on humans, but we
think of them as parasites and nasty microbes, not predators.

>  After humans became 
>  numerous, you can imagine specialized predators hiding in our midst, 
>  disguised as us, but you get two questions:
> 
>  (1) Where the hell did they come from?

Earlier they were preying on monkeys in the jungle, but as people became
more plentifull than monkeys some of them changed prey. Then we perhaps
had a sympatric speciation event, and the modern vampire evolved.

>  (2) Why haven't we noticed they exist?

Because they are good at it? Have we looked for them? Sure, we wouild
have noticed if tens of freshlyn drained corpses turned up in London
each night, but what if 5% of the brain cancer incidence is explained by
vampires draining the <mumble> from the victims mind? 

/Par

-- 
Par              	                          usenet@[EMAIL PROTECTED]
"Errors have been made.  Others will be blamed.