
DIGEST
                        Artificial Life Digest, Number 9
 
                            Monday, March 26th 1990
 
Issue's Topics:
 
                                Emacs compatible
               Initial investigations into Artificial Life (Long)
                  Genetic Algorithms and (non)-binary alphabets
                              SAB90 Call for Papers

 
----------------------------------------------------------------------
 
Date: Mon, 26 Mar 90 11:18:29 EST
From: Eric T. Freeman <efreeman>
Subject: Emacs compatible

This is our first attempt to create a emacs-compatible digest.  Direct
all problems to alife-request@iuvax.cs.indiana.edu.

Thanks,

Eric Freeman

------------------------------
 
Date: 22 Mar 90 16:54:29 GMT (Thu)
From: Harold Thimbleby <hwt%compsci.stirling.ac.uk@nsfnet-relay.ac.uk>
Subject: Initial investigations into Artificial Life (Long)

I've posted this note a couple of times to alife, but I've not
seen it appear ... maybe it's got lost over the Atlantic.

I enclose the following jottings for comment, feedback, extension, etc.
I know the net has is having a fuss over spurious philosophical issues 
--- I'd also be interested to hear what people FEEL about these sorts
of issues, whether they are relevant etc., as well as what they think
about their correctness!
Of course, helpful additions will be welcome!

           Initial investigations into Artificial Life
                        Harold Thimbleby
                  Wednesday, February 21, 1990

1.      If you watched a film of animals on television, you would
say  that  what  you  could  actually see in front of you --- the
television --- was not alive in any sense, but you'd  agree  that
what  was  filmed  was  or  had  been  alive.  If now you watch a
computer screen showing something claimed to be AL, would you say
it  was  alive, or merely a film of something that may or may not
be alive?

2.      Turing Completeness is neither necessary  nor  sufficient
for  AL.   The  existence of (say) worms which, although they can
compute limited functions, cannot be  organised  into  a  general
computational  device,  shows  that  Turing  Completeness  is not
necessary for life.  Insufficiency is easily shown by considering
an  actual  Turing  Machine:  whatever  it  was  doing,  no human
observer would want to say that it was alive!  At best  it  would
use symbols and be too slow or too mysterious.

3.      Real life dies.  Does life embedded in silicon die?  What
would the point of death be for AL?

4.      The Turing Test does not help.  Imagine the test  between
a  computer  and  a cat, with a human interrogator.  The computer
merely has to do nothing, and then  the  human  cannot  tell  the
computer  from  the  cat.  Therefore the computer is alive!?  No,
the  Turing  Test  is  a  refutation  procedure:  only  when  the
interrogator  can  see  the  difference  do you know that the two
tested objects are distinguishable.

5.      Consciousness is not sufficient for AL.  A machine  might
be  able to pass the Turing Test, yet still be `just' a computer.
The  Turing  Test  tests   for   intelligence,   and   presumably
consciousness, not for life.

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.

7.      Computer  viruses  are  certainly  as  alive   as   their
biological  counterparts.   An 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.

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.

9.      Life   can   be   defined   as   a   relationship    with
uncontentiously  alive  beings,  such as humans.  Worms are alive
(by common consent).  Many people who have never talked to  worms
have  a working relationship with computers.  Therefore computers
are alive.

10.     Life is a vague concept.  The  argument  goes  along  the
well-worn  Sorites  paradox  lines:   A computing device with one
gate is clearly  not  alive.   Adding  a  gate  to  a  non-living
computing   device   does  not  make  it  alive.   Therefore  (by
induction) no number of gates is sufficient to make  a  computing
device  alive.   (The  proof  can be considerably strengthened by
making `one gate' any member of a set of appropriate components.)

11.     Either you disagree with the last point, or you  have  to
agree  that  a  single  neuron  (or any other biological building
brick) is alive.   It  follows  that  life  is  not  an  emergent
property,  since  it  can be found in any identifiable biological
component.

12.     A solution to the Sorites paradox is  that  the  observer
permits several gates to be added all at once.  ``It wasn't alive
then, but now it is.''  The corollary is that when putative  life
is analysed at too low or too frequent a level of detail it never
appears to be alive.

13.     Is AL accountable?  If AL replicates autonomously, who is
responsible for the `wild' (or ferral) animals thereby created?

14.     In British Law, you  need  a  licence  to  propagate  the
African  Violet  (a pleasant little flower), because you would be
competing against the originator of the African Violet strain you
worked from.

15.     Destructiveness is easier to  achieve  than  cooperation.
Is  it  a  coincidence  that  the  largest  things  at the Second
Artificial Life Workshop were destructive?

16.     All advanced technology has  had  an  unexpectedly  large
impact  on  toys and recreation.  (Contrast the first predictions
for the number of computers a country required  with  the  number
that  are now used in arcade games.)  AL can likewise be expected
to have a major impact on toys.  Well, at least AL should be fun.

17.     If researchers can learn anything  about  life  from  AL,
then  children  ought  to  be able to learn how to be biologists,
ecologists, ethologists.  Slogan:  Make AL educational!

18.     If AL turns out to be difficult, or even  a  non-starter,
at  least  we  will  have  a  greater appreciation just for being
alive.

19.     Searle uses his Chinese Room thought experiment to  argue
that  computers  could  not  understand  Chinese  (and  hence  by
implication other natural languages).  He claims  that  he  would
not  be `conscious' of understanding Chinese.  Here, I agree with
him.  But there are two  intriguing  issues:   first,  Searle  is
obviously  the  hardware implementing the software of his Chinese
rule book.  Therefore, it is not surprising that he, as hardware,
is  not  conscious:  the rule book is conscious, or at least some
combination of rule book plus Searle, rather than  Searle  alone,
is  conscious.   The  second  point  is, granted Searle denies he
understands Chinese, but what happens when  the  outside-the-room
Chinese  speaker  asks the room whether `it' understands Chinese?
The only sensible answer, by assumption, is that the room replies
that, yes, it does!

20.     My  conclusion  from  Searle's  experiment  is  that  the
consciousness  of part of an organism (in this case, a room, rule
book, and Searle himself)  cannot  be  relied  upon  to  form  an
accurate image of the consciousness of the entire organism.

21.     If Searle has a rule book, then I see  no  reason  why  a
computer could not implement its rules.  First question: could an
outside observer  tell  that  we  have  replaced  Searle  with  a
computer (shades of the Turing Test)?  The next question: whether
the computer is alive or not, or thinks itself  to  be  alive  or
not,  is immaterial to the answers it gives to an outside Chinese
interrogator!

22.     If the rule book allowed Searle to answer, ``What's  your
favourite  method  of  reproduction?'', the computer could answer
the same question --- with the same answer.

23.     The interesting question for AL is whether the rule  book
postulated by Searle can exist, even in principle.

24.     Maybe be AL will evolve life more intelligent than we are
but there is no reason to suppose that intelligence  and altruism
are  in  any  way related.  We may be much worse off, even though
there is 'life' that could, but only in principle, help us  solve
our tricky survival problems.

To be continued

------------------------------
 
Date:  Fri, 23 Mar 90 17:59:54 +0100
From: christer@cs.umu.se
Subject: Genetic Algorithms and (non)-binary alphabets

Is it really that important to use a binary alphabet to represent individuals
in genetic algorithms as many prominent GA people claim it to be?

Schaffer writes (in Davis' "Genetic Algorithms and Simulated Annealing" p.90):
"There is nothing sacred about a binary character set. In principle any
character set may be used. However, there are reasons for preferring binary.
The arguments have been given by Holland (Holland 1975, p.71) and by Smith
(Smith 1980, p.56) and some empirical evidence for the correctness of these
arguments has been presented by Schaffer (Schaffer 1984, p.107)."

I don't have access to any of the works mentioned (Hollands book is impossible
to come by - anyone has a copy he/she wants to sell?). Could someone please
summarize these reasons?

While David Goldberg (in his book "Genetic Algorithms in Search, Optimization
and Machine Learning") seems to take every opportunity to condemn the use of
non-binary alphabets. He also states 'the principle of minimal alphabets' as:
"The user should select the smallest alphabet that permits a natural expression
of the problem."

What if I'm encoding a programming language (eg LISP) in binary, I still
have to combine bits in order to decode an instruction - why not represent
the instructions and their arguments as integers right away? Especially if I
only have 5 instructions, then I would need to add 3 NOP instructions (or
whatever) to ensure that I have all 8 instructions that the 3 bits (needed
to encode the 5 instructions) decode for.

When is it reasonable to use a binary alphabet and when isn't it?

/Christer

| Christer Ericson            Internet: christer@cs.umu.se [130.239.1.101] |
| Department of Computer Science, University of Umea, S-90187 UMEA, Sweden |
| "Track 0 sector 0 must *always* load into page 8!" -Krakowicz' first law |

------------------------------
 
Subject: SAB90 Call for Papers
Date: Mon, 26 Mar 90 09:42:30 EST
From: Stewart Wilson <wilson@think.com>

						March 26, 1990

Dear Colleague,

    Enclosed is the Call for Papers for the conference "Simulation of 
Adaptive Behavior: From Animals to Animats" that will be held in Paris 
in September, 1990, and is chaired by Jean-Arcady Meyer and me.  We believe 
that study and simulation of adaptive animal behavior is an important and 
potentially fruitful new trend in artificial intelligence.  The idea of the 
conference is to bring together people who are trying to understand adaptive 
behavior in real animals with people attempting to create adaptive artificial 
animals.  Each group has much to learn from the other.  Since each group also 
does considerable modeling, we have emphasized computer simulations-or,
where possible, physical realizations-as a good vehicle for presenting 
and comparing ideas.

.    From initial reactions, the conference has an exciting and timely
theme, and we have been fortunate to assemble an outstanding program
committee.  We very much hope you will contribute a paper and will be able
to attend.  Papers will be reviewed by members of the program committee
and will be published in a proceedings volume available shortly after
the conference.  For information, when it is ready, on arrangements for 
attending the conference, kindly confirm this message and include your 
postal address.  We look forward to seeing you "a Paris"!

Yours sincerely,
Stewart Wilson

    

                               Call for Papers

           SIMULATION OF ADAPTIVE BEHAVIOR: FROM ANIMALS TO ANIMATS

                An International Conference to be held in Paris
                            September 24-28, 1990

        The object of the conference is to bring together researchers in
        ethology, ecology, cybernetics, artificial intelligence, robotics,
        and related fields so as to further our understanding of the behaviors
        and underlying mechanisms that allow animals and, potentially,
        robots to adapt and survive in uncertain environments.

        The conference will focus particularly on simulation models in
        order to help characterize and compare various organizational principles
        or architectures capable of inducing adaptive behavior in real or
        artificial animals.

        Contact among scientists from diverse disciplines should contribute
        to better appreciation of each other's approaches and vocabularies,
        to cross-fertilization of fundamental and applied research, and
        to defining objectives, constraints, and challenges for future work.

        Contributions treating any of the following topics from the
        perspective of adaptive behavior will receive special emphasis.

   Individual and collective behaviors   Autonomous robots
   Action selection and behavioral       Hierarchical and parallel organizations
    sequences                            Self organization of behavioral
   Conditioning, learning and induction   modules
   Neural correlates of behavior         Problem solving and planning
   Perception and motor control          Goal directed behavior
   Motivation and emotion                Neural networks and classifier
   Behavioral ontogeny                    systems
   Cognitive maps and internal           Emergent structures and behaviors
    world models

        Authors are requested to send two copies (hard copy only) of a
        full paper to each of the Conference chairmen:

          Jean-Arcady MEYER                 Stewart WILSON
          Groupe de Bioinformatique         The Rowland Institute for Science
          URA686.Ecole Normale Superieure   100 Cambridge Parkway
          46 rue d'Ulm                      Cambridge, MA  02142
          75230 Paris Cedex 05              USA
          France
          e-mail: meyer@FRULM63.bitnet      e-mail: wilson@think.com
                  meyer@hermes.ens.fr

       A brief preliminary letter to one chairman indicating the intention to
       participate--with the tentative title of the intended paper and a list 
       of the topics addressed--would be appreciated for planning purposes.  
       For conference information, please also contact one of the chairmen.

        Conference committee:

          Conference Chair              J.A. Meyer, S. Wilson

          Organizing Committee      Groupe de BioInformatique.ENS.France.
          and local arrangements    A. Guillot, J.A. Meyer, P. Tarroux,
                                       P. Vincens

          Program Committee     L. Booker, USA          R. Brooks, USA
                                P. Colgan, Canada       P. Greussay, France
                                D. McFarland, UK        L. Steels, Belgium
                                R. Sutton, USA          F. Toates, UK
                                D. Waltz, USA

        Official Language: English

        Important Dates

           31 May 90  Submissions must be received by the chairmen
           30 June 90  Notification of acceptance or rejection
           31 August 90   Camera ready revised versions due
           24-28 September 90  Conference dates


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