[PW] Percentage of Life-eating-life lifeforms on earth?

[Brian Whatcott]

At 02:34 PM 10/9/2007, you wrote:
>I'm wondering if anyone has seen any approximations of what 
>percentage of lifeforms on earth (and by life let's say 
>multi-cellular forms on up) eat other forms of life?  Thanks.  John Ptak
>                         Specializing in rare and significant works 
> in the history of science as well as indelible and iconic images.
>
>                         J.F. Ptak  JF Ptak Science Books LLC & 
> Longstreet Antiquarian Maps


Interesting question.
As a first cut, suppose that all plants sustain themselves on mineral 
nutrients,
  water and sunlight. And suppose that all animals eat animals or vegetables.

Then what proportion of lifeforms are animal, and what proportion are 
vegetable?
  This URL suggests that the numbers of species are unknown
  http://www.livescience.com/strangenews/070803_gm_numberspecies.html

It suggests to me that the proportion classified as animal versus 
vegetable is also
unknown.   So your question is apparently unanswerable.
At times like this, one is tempted to exptrapolate from a sample.
Suppose we throw down a 2 ft wooden hoop, and count animals and vegetables
to be found in that ring....

In my grassy backyard, there might be ten thousand blades of grass,  a thousand
  macroscopic creepy-crawlies, and a huge number of bacteria.

Yep: even a wild estimate from a random sample is very very uncertain, I'd say!


Brian Whatcott    Altus OK    Eureka!