Re: Life's complexity: self-organization, evolution or both?

On Mon, 17 Sep 2007 03:03:43 GMT, Bill Morse
<wdNOSPAmorse@xxxxxxxxxxxxxxxx> wrote:

Perplexed in Peoria wrote:



(snip)

That may well be true, but organism complexity and ecosystem
complexity are completely different animals. NS (i.e. reproduction
and genetic inheritance) is central in explaining organism complexity.
But NS isn't much involved in explaining ecosystem complexity.

Arguable. One doesn't ordinarily think of ecosystems as having excess
reproduction. But they might be considered to have heritable fitness. I
don't think one should completely dismiss the idea of ecosystems competing.

Ecosystems are MUCH simpler than organisms, and their evolution is
something even a physicist can understand.

This seems extraordinarily unlikely on the face of it. Ecosystems are
composed of a large number of organisms. All our experience with other
systems tells us that aggregations of large numbers of subunits results in
greater complexity than that exhibited by any of the subunits.

It depends on how you count "number of subunits". Also, the patterns
of interaction between units within an organism are quite intense
whereas those between units within an ecosystem are rather weaker.
Yes, if somebody catches and eats you, that might be considered
intense from your point of view. But you have to look at the
population and the probability of being eaten. The nervous and
hormonal control systems, not to mention the genetic regulatory
control systems, within an organism and within a cell are much more
deterministic.

But without trying to measure complexity to see which one "wins", you
must consider that organisms must contribute to the success of the
ecosystem in which they live if they are to survive and reproduce. So
yes, indeed, ecosystems are strongly affected by evolution and change
with evolution. So why not just say that they evolve, even though the
mechanism is rather different from evolution of populations and
species.


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