Copy Link
Add to Bookmark
Report
Alife Digest Number 022
ALIFE LIST: Artificial Life Research List Number 22 Monday, May 21st 1990
ARTIFICIAL LIFE RESEARCH ELECTRONIC MAILING LIST
Maintained by the Indiana University Artificial Life Research Group
Contents:
biospheres
What is the condifence of a Lyapunov exponent?
ERL and Lamarckian Evolution, emergence, and Intelligence
Science News Article...
----------------------------------------------------------------------
Date: Wed, 16 May 90 14:59:58 -0400
From: fritz_dg%ncsd.dnet@gte.com
Subject: biospheres
Filling some holes in my AL Digest series by ftp (was it my gateway?) I have
come accross Harold Thimbleby's posting (Digest 9) on AL for the 1st time, and
would like to take a swing at an issue or two, and add some comments of my
own.
>3. Real life dies. Does life embedded in silicon die? What
>would the point of death be for AL?
Is life metabolism :-)? Most dramatic exposition, for me at least, was
Dawkins' Selfish Gene, which helped frame the question, what is it that
"lives", the phenotype or the genetic information?
>6. We know too much about biological life, so we get
>confused with such examples as viruses, plant seeds, eggs and so
>on. What about a body undergoing autolytic decomposition: part
>of it is alive! Perhaps we should define life as obviously
>alive, and exclude things that are not observable to the naked eye.
>...
>8. What if a lump of rock on the beach was alive? How would
>you know, and even if you did, there would be no consequences for
>believing it. The rock might, of course, be silicon.
Without a better idea of what life is we don't know what to look for
nor how to recognize it. Until then, our planet's organic chemistry
life is the best guide we have as to what life is.
>7. Computer viruses are certainly as alive as their
>biological counterparts. And what is more, computer viruses are
>out of control of their creators. They are far more alive than
>any AL simulation that is stopped when its computer is switched off.
Which suggests that a definition of the biosphere in which a
phylogenetic assemblage of life forms exists is as important as
describing the life itself. If computer viruses (CVs) are alive, they
are so with respect to a human generated biosphere of copper wire, RAM's,
processors, and magnetic oxides. You might say CVs have parasitized
our culture but not our physical bodies...
.
Perhaps knowing where life can take root is as important as knowing it's
elements. Perhaps physically independent life on our planet at our quantal
scale cannot be qualitatively different than what we already see--
that is, our planet already supports the only diverse form of macro-chemical
phylogeny it is capable of. (Or _is_ it a case of the niche being usurped?)
However, what if new environments emerge from the activities of life forms based
on older environments? To the extent that our human social and technological
base is stable, can it provide the environment for novel forms (of genesis)?
Certainly _within_ a genesis that's the case, we are all fairly dependent on
chlorophyll... Therefore, if humanity provides the stable material sources,
can another type of independent _physical_ life bootstrap itself into
evolutionary viability?
If these Homo-granted sources constitute the environment where the
adult-phenotype interacts, though, isn't it really just like any ol' computer
simulation? But, what if the sources just provide an embryonic environment,
and the adult plays around where we do (in the mud). Do we get a real critter?
(Poor thing, it gets its measure taken in two different worlds!) What I'd like
to see is someone's genetic driven simulation incubate in its turing box, and
then pop out and wander around the auditorium on (its/their) own...
but don't forget to close the (natural selection) loop!
Dave Fritz fritz_dg%pogo.dnet@gte.com
------------------------------
Date: Wed, 16 May 90 21:09:14 -0500
From: "Federico A. Cuello" <cuello@uxh.cso.uiuc.edu>
Subject: What is the condifence of a Lyapunov exponent?
>From cuello@uxh.cso.uiuc.edu Wed May 16 21:05:28 1990
Received: by uxh.cso.uiuc.edu
(5.62+/IDA-1.2.8) id AA28181; Wed, 16 May 90 21:05:27 -0500
Date: Wed, 16 May 90 21:05:27 -0500
From: "Federico A. Cuello" <cuello@uxh.cso.uiuc.edu>
Message-Id: <9005170205.AA28181@uxh.cso.uiuc.edu>
To: alife-mailing-list
Subject: Confidence tests for Lyapunov exponents?
Cc: cuello@uxh.cso.uiuc.edu
Status: R
The procedure for uncovering Lyapunov exponents from a time series
has become a generalized test for proving nonlinearity/chaotic behavior
(Eckmann et. al. [1986], _Phys. Rev. A_ 34[6]: 4971-4979; Wolf et al.
[1985], _Physica 16-D_, 285-317).
I have a few questions:
1) Is it feasible to ask for the statistical confidence of a positive
Lyapunov exponent uncovered from a time series?
2) If so, does there exist such a test? Can any of the members of this
mailing-list provide me with some references?
Regards,
Federico A. Cuello <cuello@uxh.cso.uiuc.edu>
------------------------------
Date: Fri, 18 May 90 16:23 EST
From: Jonathan Schull <J_SCHULL%HVRFORD.BITNET@CORNELLC.cit.cornell.edu>
Subject: ERL and Lamarckian Evolution, emergence, and Intelligence
With regard to recent discussions of ERL, Lamarckian evolution,
Baldwin effects and the power of evolutionary algorithms, I'd
like to put in a plug for my just-published paper,
"Are Species Intelligent?"
Behavioral and Brain Sciences 13(1) 1990 63-108.
(reprints available)
The basic argument is that biological species evolving under neo-
darwinian mechanisms may process information and solve problems
so effectively, and in ways which are so similar to those used by
intelligent animals, that they should be considered intelligent
systems. Whether the argument actually goes through for
biological species remains to be seen, but it should apply to
artificial life systems, too. The paper tries to develop a
conceptual framework for approaching such questions
theoretically, empirically, and experimentally (Artificial
Lifers, take note), and also tries to show that inter-demic
selection, Baldwin effects, and other "kosher", but often
neglected, development-evolution interactions increase the power
and scope of Darwinian evolution in many important and impressive
ways. The latter point may be of some use in the design of AL
simulations, as Fritz's and Ackley's discussion suggests.
Because the paper is accompanied by some 25 commentaries from a
variety of disciplines (including philosophy, biology, artificial
intelligence, cognitive science, genetic algorithms, and
psychology) it touches on many issues which should be of interest
to Artificial Lifers, even those who want to shy away from fuzzy
concepts like "intelligence". The issue which inspired this note
concerns what Ackley calls "Baldwin Effects".
"Communication" can occur between (individual's) developmentally-
achieved adaptations and populational (evolutionary) adaptaton
even when Lamarckian inheritance is impossible (e.g., in life as
we know it). The communication occurs through the effects of
developmental adaptations on selection pressures. In the paper,
and in the reply to the commentaries I suggest that the term
"organic selection" be applied generically to a wide range of
phenomena (including "Baldwin effects", but also other non-
behavioral phenomena such as phenocopy, genetic assimilation,
behavioral drive and canalization, all of which may have AL
analogues).
Because Artificial Life may be the first modern discipline which
is able and willing to explore these important but neglected
aspects of evolution, (see, e.g., Hinton and Nowlans paper in
Complex Systems 1:495-502), I thought I'd call the issue, and the
terminology, to your attention. "Organic selection" was
Baldwin's original term, before he began a (successful) campaign
to claim credit for an idea which several other theorists had at
about the same at the turn of the century. The subsequent
proliferation of terms referring to specific physiological
mechanisms and levels of organization have made it hard to see
the common content and import of the phenomena, which is why a
generic term may be desirable. I vote for "organic selection",
but in any case, commend the phenomena and the issues to your
attention.
I'd be interested in hearing about any work which bears on such things.
Jonathan Schull
Department of Psychology
Haverford College Haverford PA 19041
in%"J_Schull@HVRFORD.bitnet"
(215) 896-1237
------------------------------
Date: Mon, 21 May 90 15:25:43 MDT
From: cgl%pullet@LANL.GOV (Chris Langton)
Subject: Science News Article...
The current issue of Science News (May 19, 1990: V137, no. 20)
has a report on the ALife ][ workshop as its cover story.
The cover of the issue shows a field of flowers grown using
L-Systems rendered by P. Prusinkiewicz of the U. of Regina
(the "Master Blaster" himself!)
Cheers!
Chris Langton
Complex Systems Group
MS B213, Theoretical Division Phone: (505) 667-9471
Los Alamos National Laboratory Email: cgl@LANL.GOV
Los Alamos, New Mexico, USA
87545
------------------------------
End of ALife Digest
********************************
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=---=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
= Artificial Life Distribution List =
= =
= All submissions for distribution to: alife@iuvax.cs.indiana.edu =
= All list subscriber additions, deletions, or administrative details to: =
= alife-request@iuvax.cs.indiana.edu =
= All software, tech reports to Alife depository through =
= anonymous ftp at iuvax.cs.indiana.edu in ~ftp/pub/alife =
= =
= List maintainers: Elisabeth Freeman, Eric Freeman, Marek Lugowski =
= Artificial Life Research Group, Indiana University =
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=---=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
End of Alife Digest
********************************
