r norman  wrote in
news:cnaq3q$2l46$1{at}darwin.ediacara.org: 

> On Mon, 15 Nov 2004 03:57:09 +0000 (UTC), "Number 6"
>  wrote:
> 
>>Size isn't everything so we hear. The dinosaurs were pretty big and
>>now we have discovered small human creatures. So given the size of a
>>planet there must be a physical maximum size for its mammals. For
>>instance, for a given force due to gravity the heart would need to be
>>big enough to circulate the blood.Same for trees - how high can they
>>get? The fluids need to be pumped up to the leaves.
>>Therefore how small can we get and how big can we get and if the
>>planet had less could the creatures be bigger? (conversely for a large
>>planet). 
>>
> 
> The subject you ask about is generally called "Scaling in Biology".   
> 
> There are a number of sources that you should read.
> 
> "On Being the Right Size", JBS Haldane, 1928)
>   http://irl.cs.ucla.edu/papers/right-size.html
> 
> "Scaling : Why Is Animal Size so Important?", 
> K Schmidt-Nielsen, 1984
> 
> and, of course,
>  "Dinosaurs, dragons, and dwarfs: The evolution of maximal body size"
> GP. Burness,, J Diamond,and T Flannery, 2001
> Proc Natl Acad Sci U S A. 2001 December 4; 98(25): 14518-14523
> http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedi
> d=11724953 

I have (and very much enjoy) Schmidt-Neilsen's book. Thanks for the other  
references. I don't recall that Schmidt-Neilsen discusses size in aquatic 
animals. Higher gravity would seem to tend to reduce the size of land 
animals (other things being equal), but I don't know whether the 
increased gravity would significantly affect aquatic species.

Yours,

Bill Morse
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