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

On Thu, 20 Sep 2007 02:10:28 GMT, "Perplexed in Peoria"
<jimmenegay@xxxxxxxxxxxxx> wrote:


"John Harshman" <jharshman.diespamdie@xxxxxxxxxxx> wrote in message news:u8jIi.621$6p6.331@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Bill Morse wrote:
Now obviously the change is due to "the ability of different organisms to
outcompete others in particular environments." But in some of these
communities, the interactions between different organisms, the individuals
helping "create each others' environments", becomes a tight enough loop
that the whole community does behave in some sense as a superorganism.

I can't think of any such communities. There are tight interactions, but
they tend to be between species pairs at the most. And the cases in
which species pairs are always found together, never separately, are
surprisingly few. Even if species A depends absolutely on species B in
some locality, it may depend on species C in some other locality.

I'm not sure that the crucial interactions involved here are 'loops'. In
the cases that Bill mentions in which there seems to be a sharp and
complete change in the member species in the community, I suspect that
it is due to a change in the single primary-producer species. There may
well be loops at the higher trophic levels, but I suspect that most
communities are supported by a single Ayn Rand style rugged individualist
species which is beholden to no other species but is directly or indirectly
grazed and parasitized by everyone else. Change the identity of that
key primary producer, and the identities of every other player perforce
must change too.

Remember that the ecosystem consists of the organisms plus the
environment. There may not be such tight interactions between species
to maintain the system, but the definitely can be a tight interaction
between one key species, likely the primary producer as you suggest
(or even a microbe that the primary producer depends on) and the
physical environment. Plants alter the nature of the soil, the water
availability, and the sunlight availability in their immediate
environment. The change in these environmental factors may be
detrimental to other species invading. So it is really the
plant-environment combination that is the important factor.
Technically that becomes an ecosystem phenomenon.

.

Relevant Pages

  • Re: Lifes complexity: self-organization, evolution or both?
    ... communities, the interactions between different organisms, the individuals ... helping "create each others' environments", ... I can't think of any such communities. ... they tend to be between species pairs at the most. ...
    (talk.origins)
  • Re: Lifes complexity: self-organization, evolution or both?
    ... communities, the interactions between different organisms, the individuals ... helping "create each others' environments", ... I can't think of any such communities. ... they tend to be between species pairs at the most. ...
    (talk.origins)
  • Re: Lifes complexity: self-organization, evolution or both?
    ... communities, the interactions between different organisms, the individuals ... becomes a tight enough loop ... I can't think of any such communities. ... they tend to be between species pairs at the most. ...
    (talk.origins)
  • fringe populations as a generic bio-system parameter
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    (sci.bio.evolution)
  • Re: Unambiguous definition?
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    (uk.environment.conservation)
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