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

On Thu, 13 Sep 2007 19:06:31 GMT, John Harshman
<jharshman.diespamdie@xxxxxxxxxxx> wrote:

dkomo wrote:

In Roger Lewin's _Complexity: Life at the Edge of Chaos_, at the end of
Chapter 7 "Complexity and the Reality of Progress", there is a paragraph
that nicely summarizes the differences between two major paradigms --
that of evolution and that of complex systems theory:

"The pure Spencerian view of the world, therefore, is that increased
complexity is an inevitable manifestation of the system and is driven by
the internal dynamics of complex systems: heterogeneity from from
homogeneity, order out of chaos. The pure Darwinian view is that
complexity is built solely by natural selection, a blind, nondirectional
force; and there is no inevitable rise in complexity. The new science
of Complexity combines elements of both: internal and external forces
apply, and increased complexity is to be expected as a fundamental
property of complex dynamical systems. A fundamental property of
complex adaptive systems is the counterintuitive crystallization of
order -- order for free, in Stu Kauffman's terms -- upon which selection
may act. Such systems may, through selection, bring themselves to the
edge of chaos, a constant process of coevolution, a constant adaptation.
Part of the lure of the edge of chaos is an optimization of
computational ability, whether the system is a cellular automaton or a
biological species evolving with others as part of a complex ecological
community. At the edge of chaos, bigger brains are built."

Does this mean that very few species ever find themselves on the edge of
chaos? Because only a few lineages have ever built bigger brains. It
would seem to me that if there were some universal principle acting
here, it would be acting everywhere. That's what universal means. So, if
big brains get built as a pure consequence of self-organization, why
don't all animals have big brains? Why, for that matter, don't plants
and fungi have them?

"Is human consciousness to be found there, too?"

What does he mean, "too"?

I don't go along with Kaufman's notion of always reaching out to the
"edge of chaos" to find organization and order. But still there are
innumerable examples of complex systems selected by biology. Life,
itself, is the first and most dramatic example. Once you develop a
system of sufficient organizational complexity, a complexity which
includes self-replication, it naturally selects itself over any
alternative which cannot reproduce. I would argue that the cellular
regulatory systems responsible for the eukaryotic cell, for the animal
"bauplans" of development, for the organizational principles
underlying sensory and motor pattern generation and detection, the
homeostatic regulatory systems found extensively in animals and even
to some degree in plants are all "complex systems" selected by
biology. That not all evolutionary pathways have selected for large
brains is no different from the fact that not all evolutionary
pathways have selected for internal skeletons or for quadrupedal
locomotion (which can then be secondarily modified into bipedal) or
for autotrophy or for nitrogen fixation or for ..... (fill in your
favorite feature here). Different strokes for different folks. But
organizational complexity provided by complex dynamic systems is
simply part of the tool box, just as is the biochemical metabolic
machinery or the molecular biology of the gene. Biologists are
accustomed to having to take GChem and Organic Chem and Biochem to
understand how cells work. I would argue that biologists should also
have to take advanced calculus and systems theory to understand how
cells work.

I think the problem might be in thinking that more-and-more complexity
is a necessary outcome of the operation of a complex dynamic system.
There are some systems that under some conditions can produce
complexity. There are many that do not. Selection for those systems
that can produce such complexity is a part of evolution, but you have
to have the right precursors to do so; something that only some
evolutionary pathways have.

.

Relevant Pages

  • Re: Species diversity through time
    ... Gould didn't think evolution was a random walk. ... I was going to address the selection issue but ran out of steam. ... of increasing complexity, ... explanatory ability of the received view in modern biology. ...
    (talk.origins)
  • Re: Species diversity through time
    ... Gould didn't think evolution was a random walk. ... I was going to address the selection issue but ran out of steam. ... of increasing complexity, ... explanatory ability of the received view in modern biology. ...
    (talk.origins)
  • Re: Evolution increases the computational ability of organisms.
    ... >> Fluctuating selection would satisfy Gould equally well. ... >> Probably the major theme is that complexity follows a random walk ... You were trying to justify a claim that genome length increases through ...
    (talk.origins)
  • Re: Species diversity through time
    ... again like an ordinary random walk. ... Gould didn't think evolution was a random walk. ... He knew that there was such a thing as natural selection, ... of increasing complexity, ...
    (talk.origins)
  • Re: Species diversity through time
    ... That's why I say evolution is a random walk in Gould's view. ... He knew that there was such a thing as natural selection, ... of increasing complexity, ... I only got started seriously on the subject areas of emergence and self-organization in the last two months after reaching a state of utter exasperation with the explanatory ability of the received view in modern biology. ...
    (talk.origins)