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Author Topic: GA evolves 1,800 bits of CSI?
Mark Elkington
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Icon 5 posted 26. February 2002 06:24      Profile for Mark Elkington   Email Mark Elkington   Send New Private Message       Edit/Delete Post 
The following study uses a genetic algorithm to generate digital data to configure a programmable electronic chip to produce a nontrivial, functioning circuit.

The resulting data file of some 1,800 bits appears to contain complex, specified, and novel information.

Is it in fact CSI? If so, was it "smuggled in" from elsewhere, and how? Some analysis of a relatively simple and concrete example such as this might help clarify these concepts.

quote:
"Thompson’s genetic algorithm created 50 random bit strings of artificial dna, each 1,800 bits long, the number of configuration bits needed to describe fully the wiring in those 100 cells. These bit strings constituted the initial 50 individuals to be run through the evolution process. "For each of the individuals in turn," Thompson explains, "I take the bit string and download it onto the chip. Now that individual is physically in silicon, and I pump in five bursts of 1 kilohertz and five bursts of 10 kilohertz in random order." He then tests these individuals to see how well they do at producing an output that’s different for the different inputs, considering that unless he is extraordinarily lucky, all the bit strings in the first few generations "will be as bad as possible at doing any task." For this reason, it’s not sufficient to say one individual works and another doesn’t. Thompson had to develop a fitness test that allows him to say one individual may perform slightly less abysmally than the next, which he did by looking for cases in which the average of the outputs during a 1 kilohertz burst was as different as possible from the average during a 10 kilohertz burst. After testing and scoring all 50, the genetic algorithm randomly chooses parents for the next generation, with a built-in preference for those that scored best on the fitness test. The single best individual on the test is also copied over unchanged to the next generation, a useful addition that computer scientists call "elitism." These chosen parents are mated, their bit streams commingled, with a pinch of mutations thrown in ("You don’t want to screw things up too much," he says) to make 50 new offspring. Then the process begins again. After 5,000 generations and two weeks of computer time, the computer was distinguishing between the two tones."


Evolving A Conscious Machine

The researcher's home page is:
Adrian Thompson's Hardware Evolution Page


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Icon 1 posted 26. February 2002 08:57      Profile for Moderator   Email Moderator   Send New Private Message       Edit/Delete Post 
Thanks for your post Mark. This data is very exciting and informative. We would like, however, to provide a suggestion for the way in which you frame topics in subsequent posts.

Seeing that Brainstorms is in the early stages of existence, we are going to take opportunities like this to set the context and direction that this board takes.

Brainstorm posters should always frame initial topics in the form of an intuition, argument or hypothesis to help fellow Brainstorm readers better understand and respond to the context of your data. For example, (using Mark's topic) you could have started the post by indicating that you have an intuition/prediction that we will find that genetic algorithms can readily produce large levels of CSI. You could then have cited the intriguing results of Adrian Thompson's work (1800 bits of CSI) and possibly others to back up your hypothesis.

[ 26 February 2002: Message edited by: Moderator ]


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Mark Elkington
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Icon 1 posted 26. February 2002 21:30      Profile for Mark Elkington   Email Mark Elkington   Send New Private Message       Edit/Delete Post 
Fair point - rechecking the Brainstorm manifesto I see this is mentioned there.

My intuition here is that GAs are capable of producing some seemingly substantial information, and therefore within the ID framework it becomes necessary to determine if this infomation is CSI, and if it is de novo or merely imported CSI.

A related question is, Can small amounts of CSI be generated de novo by GAs? Because of the probability factor which seems to underpin ID theory, the answer would be yes. Yes, you can have small amounts of each quantity: Complexity and/or Specificity, but only small amounts, as a function of the probability resources available. Allowing this concession, if valid, removes the need to defend the fallacy of "zero de novo CSI". That in turn sharpens the focus on the question of practical probabilistic bounds (which I understand is already happening).

Further, I see value in closely watching the progress and limitations of Evolutionary Computing, as an empirical "sanity check" and hopefully confirmation of theoretical ID work.

For example, the following subjective observation of this field tends to back up ID intuition:

quote:
Synthetically reproduced protolife and artificial evolution in computers have already unearthed a growing body of nontrivial surprises. Yet artificial life suffers from the same malaise that afflicts its cousin, artificial intelligence. No artificial intelligence that I am aware of-be it autonomous robot, learning machine, or massive cognition program-has run more than 24 hours in succession. After a day, artificial intelligence stalls. Likewise, artificial life. Most runs of computational life fizzle out of novelty quickly. While the programs sometimes keep running, churning out minor variation, they ascend to no new levels of complexity or surprise after the first spurt (and that includes Tom Ray's world of Tierra). Perhaps given more time to run, they would. Yet, for whatever reason, computational life based on unadorned natural selection has not seen the miracle of open-ended evolution that its creators, and I, would love to see.

http://www.well.com/user/kk/OutOfControl/ch19-b.html


[ 26 February 2002: Message edited by: Mark Elkington ]


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Iain Strachan
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Icon 13 posted 27. February 2002 08:25      Profile for Iain Strachan     Send New Private Message       Edit/Delete Post 
One giveaway comment in the citation from the researcher's web-site immediately shows that this does not illustrate evolution via Natural Selection but via Unnatural Selection:


quote:

The single best individual on the test is also copied over unchanged to the next generation, a useful addition that computer scientists call "elitism." These chosen parents are mated, their bit streams commingled, with a pinch of mutations thrown in ("You don’t want to screw things up too much," he says) to make 50 new offspring.

I think we need to make clear exactly what "elitism" means. It is a widely used heuristic used in Genetic Algorithms to speed up the process of reaching a solution. What it means is that the best performing individual in the current population is preserved unchanged to the next generation. When the quote says at the end that 50 new offspring are created via mutation and crossover, it is important to realise that this 50 contains an exact copy of the best one from the previous generation. Therefore, by definition, the fitness of the best individual from generation to generation cannot decrease, it can only increase if one of the offspring happens to be better than it.

In my experience in the past with playing with GA's it was found to be almost essential to use elitism. Not only did it vastly improve the performance; in most cases it made it work, where it simply made no progress at all without elitism. The reason for this is that the best individual otherwise has to compete for resources probabilistically - selection probability being apportioned out corresponding to fitness. In a particularly large population, the fittest individual may only have a tiny fitness advantage over the rest, and may therefore only have a 1% higher probability of being selected. So it quite often occurs that beneficial mutations are just lost through bad luck. The problem is less severe for really small populations, because of the "big fish in a small pool" syndrome.

What is clear from the above is that once elitism is used, one simply can't make any claims that it's evolution via the Darwinian process of Natural Selection, because the best one is effectively immortal until someone better comes along. If the researcher had been able to demonstrate success in the algorithm without elitism, then this would be much more interesting.

As far as the other question about smuggling in CSI, there are two avenues whereby this could have been achieved:

(1) Via the "design" of the fitness function.
(2) Via the decoding strategy from the genome coding to the actual circuit in the silicon. Successful design of a GA involves careful consideration of the strategy you use.

[ 27 February 2002: Message edited by: Iain Strachan ]


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Jack Foster
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Icon 1 posted 27. February 2002 12:38      Profile for Jack Foster   Email Jack Foster   Send New Private Message       Edit/Delete Post 
I ran into Thompson’s work awhile ago, and was initially impressed. I would love to see the workings of this evolutionary system first hand to better understand what’s going on.

I think this is interesting, but the more I thought about it, the less impressive it became. As I recall, output tone is produced in first generation. Then the programmable hardware acts as high pass filter. The capability (constraint of search space) was accidentally produced by intelligent designer when the hardware was manufactured. (It’s like figuring out that a pop bottle can produce sound when you blow into it just right.) And then Fitness Function guides the "organism" through this limited space. But here’s the key sentence for me:

quote:
Because Thompson seems to be a pragmatist at heart, he has temporarily given up on evolving chips that could do anything fancier than distinguish between two sounds (in a follow-up experiment, he evolved a chip that could tell apart two spoken words, stop and go).

Thompson may be a pragmatist, but the more likely explanation for the limiting of goals is that the trajectory and potential scope of evolution is extremely limited on this platform. That’s not to say we can’t learn anything from it.


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Janitor@MIT
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Icon 1 posted 27. February 2002 15:59      Profile for Janitor@MIT         Edit/Delete Post 
It may be a damning admission to make, but I can’t say that I fully understand CSI as formally defined by Dembski. (I rather hurriedly scanned through his book, “The Design Inference.” However, I think I do understand the intuit that Dembski attempts to formalize.

A few months back I was rereading Altenberg’s “The Schema Theorem and Price’s Theorem,” which proffers the “canonical,” “standard,” or “generic” dynamical form of the evolutionary algorithm. I found myself wondering if the algorithm is itself an instance of CSI?

I think Dr. Dembski would insist that CSI is a reliable indicator of design. So, if the canonical evolutionary algorithm is an example of CSI do we have a false positive or have we simply inferred that evolution is designed? A bit of a dilemma?

Many questions follow: The algorithm is definitely “Darwinian,” but does it accurately describe the process of biological evolution? The algorithm also certainly resembles those evolutionary design strategies employed by engineers. But does it accurately represent an intelligent design strategy?

If the answer to both the immediately preceding questions is positive then the dilemma remains, particularly for the CSI criterion.

If the answer to the first is no and the second is yes, then Darwin has detected design!

If the answer to the first is yes and the second is no, then Dembski has detected Darwin! (LOL)

If the answer to both questions is positive then biological evolution is indistinguishable from intelligent design, and this represents a problem for the CSI criterion as a discriminatory test.

If the answer to both is negative, then the key is answering the first question first: Is the standard evolutionary algorithm an example of CSI?

I think the answer to this question has to be very, very carefully considered.

(Sorry, I didn’t mean to pepper you with so many questions. Did any of this make sense?)


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Janitor@MIT
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Icon 1 posted 04. March 2002 13:28      Profile for Janitor@MIT         Edit/Delete Post 
No response, huh? Maybe it’s not a very interesting question? Or I’ve somehow failed to apprehend some subtlety?--which is usual for me. Probably, the question just doesn’t make sense and you’re all too polite to tell me. Well, let me test your indulgence by entertaining myself:

I’ve admitted that I don’t fully understand Dembski’s CSI. But I have some basic understanding of two of its terms, information and specification. So, what if I considered Altenberg’s equation from the perspective of “specification” as it used by engineers, rather than Dr. Dembski’s more formal approach?

It appears that the theoretical object of evolutionary computation research is to somehow originate a system that exceeds, not merely the expectations of the designer, but the specifications of the designer. I would submit that the object of the research is therefore ultimately and paradoxically subversive of the theory that ostensibly supports it. In every instance where the algorithm is said to do something remarkable, all that it has really done is exceed the very vaguely defined expectations of the researcher. It’s an interesting case of how a researcher’s theoretical expectations of experimental results condition the design and conduct of the experiment, and the interpretation of results. No doubt, this is always true in science, but it’s usually the case that the experimenter’s expectations can be made concrete, presumably quantifiable, and clearly limited. But in this case the expectations cannot possibly be made concrete, quantifiable, and are definitively unlimited! If we could say exactly how the algorithm is to exceed its specifications then those would become specifications! If we could say exactly how the algorithm is to exceed our expectations then those would become our expectations! So its difficult to say exactly what this line of research is intended to achieve or how we are to understand exactly what it has achieved.

(So much of the evolutionary research program is “quasi-experimental,” so it’s difficult to know exactly what is being researched, what the expectations are, and what the results really mean. I suspect that if the algorithm ever actually met or exceeded the expectations it would be the most stunning discovery in the history of science and technology. We would have successfully harnessed the virtually limitless power and potential of evolution. Obviously, that hasn’t happened. Otherwise we would have all heard about it. Honorariums awarded, press conferences held, grant money would flow like the springtime torrents in my beloved Rockies.)

Now the requirement that the algorithm somehow exceed its specifications may be a more realistic test than the researcher’s expectations. The requirement is also a bit of a conundrum: What we are requiring is that the designer specify that his specifications be exceeded. Usually these little paradoxes and contradictions are ignored. That the algorithm can be rewritten to exceed its specifications is achievable in some narrow sense. (Since it probably is more a function of limiting expectations than exceeding specifications.) But in its (ultimate) achievement we have effectively falsified the theory that motivates the research! Even if we eliminate from consideration, what seems ineliminable, the role of the designer, his specifications, and expectations, what is really required of the algorithm is that it emulate exactly the role of the designer! This would be something of a Phyrric victory. What is really required of such an algorithm is that it emulate or implement some form of intelligence.

This is plainly seen in that body of research focused on transcending the inherent limits of the algorithm by specifying some “self-adapting” regression operator--by making it an observer/controller over its own evolutionary convergence. This is nothing more or less than an implementation of the most elementary form of machine learning. Is the solution to the basic problem in evolutionary computation to be found in artificial intelligence or machine learning?! But this approach is not obviously consistent with a Darwinian perspective on biological evolution. From the Darwinian perspective evolution is not something that life “does.” It is something that “happens” to it. Life does not directly observe and control its own evolution, except where some form of intelligence is involved. Evolution is epiphenomenal upon naturally given contingencies imposed, as it were, upon life and is not an emergent property of some sort of genomic intelligence.

But the "failure" of the “Darwin algorithm” must be placed in some perspective. The algorithm hasn’t so much failed as it has done everything that it could reasonably be expected to do. Its ironic success/failure is due to the theoretical expectations behind it and has nothing to do with its actual implementation or the results it yields.

I suspect that the idea that evolution is ultimately function optimization needs to be closely examined. What evolutionary computation has most successfully demonstrated are the limits of optimization. Limits already well understood in engineering. Innovation is required. Accordingly, the problem is most appropriately recast as one of artificial intelligence, or machine learning, of “self-adaptation,” rather than the fortuitous adaptation of Darwin.

Innovation is widely regarded as a definitive characteristic of what we call intelligence. If what we expect is that the algorithm exceed its specifications then isn’t that exactly what we are expecting of it—that it innovate?

One might argue that “innovation” is not well defined in biology. (And doesn’t even seem to be required by Darwin, although I think its fair to say that there’s a widely held belief, however ill-defined “innovation” may be, that something very much like it is required in the course of evolution, biological or computational.) But “innovation” can be defined negatively as anything that optimization cannot do. E.g., one cannot optimize something into existence. Optimization requires prior specification. (I think this fact is emphasized by Dr. Dembski.) Indeed, can anything be said to be “optimized” that in any way exceeds specifications? If in the process of optimizing we exceed specifications, we can be said to have left off optimizing and begun innovating. This partly accounts for the fact that the algorithm doesn’t meet or exceed (realistic) expectations. It can’t specify itself or revise its specifications. Specification requires innovation. Optimization does not.

Innovation is exactly what the designer/researcher does. Presumably he does so by the application of algorithms--algorithms that are not well understood by science. Because “innovation” isn’t well understood every instance of innovation definitively exceeds expectation/specification.

Now if it is indeed innovation that is required and not merely optimization than the “Darwin algorithm” serves well as a null hypothesis. Problems that it solves are not solutions to the greater problem we are confronted with. It therefore does serve a very important function in research, because knowing what the solution is not is half the job. (Frustrating as usual, the Darwin-driven research program offers us half a solution, or solutions to problems that aren’t the real problem at hand.)

So the problem as I see it is not that Dembski has detected Darwin. But that maybe Darwin has detected design, or that at least in exploring the (computational) limits of Darwin’s theory we have been led to the point where we are forced to admit that the “design of life” has far exceeded our expectations and that we cannot specify it without recognizing some “higher order” of design (innovation) is present there. Its not that Dembski’s CSI criterion fails, its that as any “mechanical” or “natural” evolutionary process converges upon CSI, it increasingly resembles what we would in any case unhesitatingly call “intelligent.” (Isn’t that what Dr. Dembski is saying?)

The algorithm plainly does not accurately represent the process of biological evolution, but that process as it really is may be indistinguishable from some (non-Darwinian) evolutionary process or evolutionary design strategy. I suspect, however, that the question remains…

My apologies to Mark Elkington for boosting his topic and to Mr. Moderator for rambling. If this post is in violation of board rules I’ll accept any recommendations by you to bring it into conformity.


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Mark Elkington
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Icon 1 posted 05. March 2002 06:31      Profile for Mark Elkington   Email Mark Elkington   Send New Private Message       Edit/Delete Post 
Janitor@MIT:

Your distinction between "optimisation" and "innovation" sounds reasonable to me. One problem, which you mention, is defining these terms.

In the case of the electronic circuit generated by the GA, if we were to reverse engineer that result and represent it as a conventional circuit schematic, it may (would?) give the appearance of an innovative design. We would see a circuit using complex, novel techniques, e.g. feedback loops exploiting secondary analog effects of the logic blocks. An engineer may well pronounce it "innovative" (and/or perhaps, incomprehensible).

Whatever the case, we have a chunk of circuitry which would take a skilled human designer a reasonable effort to functionally replicate. Whether or not it is "optimal" or "optimised" is moot; it is "innovative" inasmuch as it was not preconceived in the mind of the GA designer.

Whether it is innovative in other senses I don't know. As Iain and Jack point out, this algorithm does not accurately represent biological evolution, nor does it demonstrate unbounded innovation (far from it).

My hunch though is that useable, predicitive ID theory must be able to formally account for the origin of those 1,800 bits.

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Jack Foster
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Icon 1 posted 07. March 2002 12:35      Profile for Jack Foster   Email Jack Foster   Send New Private Message       Edit/Delete Post 
Hi Mark:

quote:
In the case of the electronic circuit generated by the GA, if we were to reverse engineer that result and represent it as a conventional circuit schematic, it may (would?) give the appearance of an innovative design.
This is one of the problems with the experiment. Thompson did not reverse engineer after each generation to show the path of evolution. I think the result would be interesting. How does random chance combined with selection make evolutionry progress on this platform vs. an engineering solution? Without a reverse engineering, we can't explore the issue.

quote:
My hunch though is that useable, predicitive ID theory must be able to formally account for the origin of those 1,800 bits.
This brings up an interesting question. When does "specified" become specified? Obviously random generation one is not specified. How about generation 2, when there has been slight advancement? Are the 1,800 bits now a "little" specified? And after generation 3, I presume the "genome" would be slightly more specified.

You see the problem. Maybe a Dembski expert can comment. (Hmm. Where are we going to find a Dembski expert around here?? [Wink] )

To the degree you call the 1,800 bits "specified", it's clear the apparent CSI is coming from the fitness function.

[ 07 March 2002, 12:39: Message edited by: Jack Foster ]

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Mark Elkington
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Icon 1 posted 10. March 2002 21:05      Profile for Mark Elkington   Email Mark Elkington   Send New Private Message       Edit/Delete Post 
Jack,

quote:
This brings up an interesting question. When does "specified" become specified? Obviously random generation one is not specified. How about generation 2, when there has been slight advancement? Are the 1,800 bits now a "little" specified? And after generation 3, I presume the "genome" would be slightly more specified.
I think you're right, though I don't see a problem with that. An intelligent designer progressing a design from a rough prototype to finished product is also moving from "little" to "much" being specified.

quote:
To the degree you call the 1,800 bits "specified", it's clear the apparent CSI is coming from the fitness function.
Yes, but what is the fitness function? It is merely the specification criterion, in this case: "Distinguish low and high tones". It is hard to see how information for solution(s) are "in" that bare specification.

Some fraction F of the total 2^1800 permutations will satisfy this function. Perhaps what we need to show is that, for this problem,

F * trials >> 10^-150

If it could be shown that

F * trials < 10^-150

would we have disconfirmed the ID hypothesis based on the notion of a "universal probability bound"?

This could be done by downloading random bit strings and testing each one. If we haven't found any solutions after a 10^150 attempts, we have our disconfirmation. Hmmm...that could take a while [Smile]

[ 10 March 2002, 21:24: Message edited by: Mark Elkington ]

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Jack Foster
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Icon 1 posted 11. March 2002 22:59      Profile for Jack Foster   Email Jack Foster   Send New Private Message       Edit/Delete Post 
Hi Mark:

Enjoyed your recent post.

If it could be shown that F * trials < 10^-150 would we have disconfirmed the ID hypothesis based on the notion of a "universal probability bound"?

In order to select for some fitness variable, an organism must possess some basic capability related to that variable. In order to select for speed, for instance, motility must exist.

In this case, output tone is produced randomly in the first generation of organisms. This shows that there's no CSI here; at least not in the first generation. Output tone for this platform, for this pre-existing phase space, is just not that improbable.

Selection at this point is based upon this basic capability. Regardless of where you are in the 2^1800 position phase space, can a path may be found to achieve the specification? How often is first generation output tone convertible to attainment of specification?

If genome with output tone is always evolvable to specification attainment, then there's no CSI here. Solutions are plentiful, and evolve with probability 1 when given appropriate fitness function.

More likely, many first generation tone producers will not be able to evolve specification attainment. Still, if they DO evolve to specification with any frequency, it should be pretty easy to estimate your variable F. And my guess is that F is way, way greater than 10^-150. Actually, it seems pretty obvious that it is, or Thompson would never have found the right first generation tone producer capable of evolving the specification.

[ 12 March 2002, 10:40: Message edited by: Jack Foster ]

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Mark Elkington
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Icon 1 posted 13. March 2002 05:38      Profile for Mark Elkington   Email Mark Elkington   Send New Private Message       Edit/Delete Post 
Jack,

I think you're probably right.

I'm reminded that the topology of the fitness landscape is the other determining factor, along with F.

If genome with output tone is always evolvable to specification attainment, then there's no CSI here. Solutions are plentiful, and evolve with probability 1 when given appropriate fitness function.

If the phase space had only one solution, i.e. F = 2^-1800, but the landscape was globally montonically increasing, or similar trivial topology, convergence would be inevitable, as you suggest.

I wonder to what extent the topology of fitness landscapes confronting biological evolution can be mapped, thereby confirming or otherwise the ability of the Darwinian mechanism to search them? The thread Coupled Mutations and Quantization of Functionality looks at this, as one example. Behe of course has given it some consideration, but only qualitatively. Perhaps such real landscapes cannot be formally mapped and quantified, in which case this approach may not yield a testable hypothesis (no matter how compelling generally)?

[ 13 March 2002, 06:27: Message edited by: Mark Elkington ]

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Iain Strachan
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Icon 1 posted 19. March 2002 03:03      Profile for Iain Strachan     Send New Private Message       Edit/Delete Post 
I have a couple of further observations on this topic. I would certainly recommend reading the two papers on this on Thompson's hardware page,
( Click Here ) which give a lot more detail than the article. The relevant papers are:

An evolved circuit,
intrinsic in silicon,
entwined with physics.

Click here to read paper in HTML format

and

Through the Labyrinth
Evolution Finds a Way:
A Silicon Ridge

Click here to read paper in Postscript format (no HTML available)

(as an aside, there is a nice bit of "intelligent design" in the titles here, which are written out in three lines as above. Counting the syllables reveals that both titles are Japanese Haiku).

The first point to note is that the program didn't evolve 1800 bits of CSI. When the final circuit was tested, they determined that only 32 of the 100 circuit components were actually used in the final solution. The circuit would still function perfectly well with the voltages on all the other elements clamped. In the second paper, they theorise fascinatingly about the use of the extra "junk" circuitry, which they classified into "useless junk" and "potentially useful junk", which was at the periphery of the circuit and would be switched in and out at different times during the evolutionary process. It is their hypothesis that this is how the evolutionary algorithm managed to find a global optimum, rather than a local optimum and getting stuck, by providing many more resources than was necessary to solve the problem. I guess this is partly motivated by the notion of "junk DNA", or the hypothesised waste material of the evolutionary process. It would be an interesting research project for someone to test out this "potentially useful junk" hypothesis with a controlled experiment.

However, the fact that only 32 elements were used implies that only 576 bits of CSI were actually evolved, not 1800.

This brings me to the second thought, which is "how many bits of information are required to specify Thompson's fitness function?" In Information Theory the "Minimum Description Length" is a way of measuring the information, in terms of the raw data itself (which may be compressed), and the algorithm needed to decode the information- the more complex the algorithm specified, the more information has been specified, because the length of the string defining the algorithm increases. Now of course, it is not possible to do this exactly - it depends on how the algorithm is implemented, what language used etc. As an attempt to get a rough order of magnitude estimate, here is my representation in C++:

code:
#define K1 (float) (1.0/30743.746)
#define K2 (float) (1.0/30527.753)
float fitness(float *y)
{
float f = 0;
int i;
for(i=0;i<5;i++)
f += K1*y[i];
for(;i<10;i++)
f -= K2*y[i];
f/=10;
if(f<0)
f=-f;
return f;
}

Thompson's constants K1 and K2 were empirically determined. I took the formula straight out of the first paper mentioned, and have assumed that the integrator counts are in the input array y, in the first five locations for the 1Khz tone and the next five for the 10Khz tone. The function could be simplified, of course - I do not know why a uniform scaling factor of 1/10 was applied, and presume it was something to do with the software implementation. In principle, it shouldn't affect the algorithm.

I compiled this with the Microsoft Visual C++ compiler (don't laugh [Wink] ), and set the optimiser to the setting that minimised the code size. This compiled to an object module of 1096 bytes, which equates to 8768 bits of information that would have to be specified to define the fitness function. The GNU gcc compiler under Cygwin did somewhat better, giving 545 bytes or 4360 bits of information. It might be thought that this is not a "fair" comparison of information specification - compilers might be inefficient, and maybe less bits could be used to specify the algorithm - for example on an 8 bit processor. But against that, I have not counted the algorithm for performing floating point arithmetic operations, which would be specified in the object code by a four-byte instruction, but would result internally in a microcoded subroutine in the Pentium processor being called, involving probably many thousands of bits of specified information.

I guess the only acid test would be to design a fpga circuit that computes Thompson's fitness function, so as to compare like with like. I would very much doubt if the resultant circuit could be made less than 576 bits (or even 1800), and so the fitness function is seen to be considerably more complex than the evolved object. This would seem to bear out Dembski's basis thesis that the information has to be put in in the form of fitness function, using intelligent design (Thompson had to tune his K1 and K2 constants to get it to work). The amount of information put in seems to be the same, or more than, the amout of information that you get out.

The key point is that while what Thompson's hardware did was extremely impressive, the final function it performed was (in my opinion) much less complex than the fitness function used to drive the evolution. If one wanted to "evolve" an fpga circuit that computed the fitness function (possibly in a more efficient implementation than a conventional chip designer would reach), then one would have to specify a correspondingly even more complex "meta-fitness" function, and so forth.

[ 19 March 2002, 07:34: Message edited by: Iain Strachan ]

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Mark Elkington
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Icon 1 posted 22. March 2002 17:25      Profile for Mark Elkington   Email Mark Elkington   Send New Private Message       Edit/Delete Post 
Iain,

Great post.

quote:
However, the fact that only 32 elements were used implies that only 576 bits of CSI were actually evolved, not 1800.
Good point, I overlooked this. In fact, the fully "clamped" 10x10 cell array (Analysis, Figure 7) shows only 21 cells, even though the associated text quotes 32.

Your coding and estimates of the data in the fitness function seem to provide a reasonable ballpark figure (I was surprised at the large difference between the compilers for such simple code?). I agree that there's probably substantial extra CSI in the floating point microcode. As you say, a more definitive estimate would require an FPGA-based fitness function, meta-function evolved of course!

Thompson's example has niggled in my mind for some time, in terms of how to explain such cases with some precision. Quantifying the CSI in the GA fitness function helps the concept of "smuggled in" CSI gel, for me at least. Nice work.

Thompson makes the telling comment:

"It is important that the evaluation method -- here embodied in the analogue integrator and the fitness function Eqn. 1 -- facilitates an evolutionary pathway of very small incremental improvements. Earlier experiments, where the evaluation method only paid attention to whether the output voltage was above or below the logic threshold, met with failure. It should be recognised that to evolve non-trivial behaviours, the development of an appropriate evaluation technique can also be a non-trivial task." (Emphasis added)

[ 22 March 2002, 17:32: Message edited by: Mark Elkington ]

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James A. Barham
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Icon 1 posted 23. March 2002 09:08      Profile for James A. Barham   Email James A. Barham   Send New Private Message       Edit/Delete Post 
Forgive me if this is a little off-topic, but I just wanted to ask for help from the ID community on understanding exactly how they interpret the mainstream research on GAs (and A-Life and robotics, more generally) from a broader, metaphysical point of view.

I have a sense of unreality reading these discussions of GAs. Thompson believes that he can literally create conscious machines by finding the correct combination of algorithms to "instantiate" intelligence. (He is not alone---Chalmers, Dennett, Rodney Brooks, Brooks' disciple, the theologian Anne Foerst, and many others agree). To me, this is utter rubbish. Which side do ID'ers come down on, here?

Let me try to pose what is troubling me this way. If it is true that organisms are literally machines, and that the "information" content of genomes is what really matters about life, and that living things are literally designed by an external intelligence similar to ours, then on what grounds can we criticize Thompson's assumption. After all, all Thompson is saying is that if we are clever enough, if we can find the right algorithm that the Creator used, then we can make plastic and silicon spring into life, just like the Creator did with proteins and nucleic acids (which, by hypothesis, have no more intrinsic tendency toward life than plastic and silicon).

Are ID'ers comfortable with this idea? That is, do they think it is conceivable that we may have to acknowlege that Brooks's robots are literally alive and accord them civil rights (as Foerst argues)? If not, then on what grounds do ID'ers draw a distinction between organisms and machines?

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