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Digital Biology

Peter Wayner writes: "Metaphors drawn from biology have always fascinated computer scientists. No one speaks of subroutines that cp themselves through undocumented remote procedure calls because talk of 'computer viruses' carries all of the portent and weight of polio, anthrax, German Measles and tuberculosis. Invoking these mysterious and deadly images is more colorful than tech speak, even if most of the so-called viruses are closer to the common cold than the black plague. Why use a three-letter acronym when a biological metaphor is available?" Wayner wrote the following review of Peter J. Bentley's book Digital Biology, which may just answer that question. Digital Biology author Peter J. Bentley pages 272 publisher Simon and Shuster rating 7.5 reviewer Peter Wayner ISBN 0-7432-0447-6 summary Does a good job of bridging the analogical gap between the worlds of computers and biology; may not be deep but will probably enlighten readers with an interest in either or both of these fields.

It should come as no surprise that the infatuation is requited because some biologists are just as fascinated with the bits that live in computers. They love to wonder whether the software crosses the line and become a sentient being, whatever that may be. They want to know whether a programmer can play Dr. Frankenstein and create life or at least an indistinguishable imitation. They are entranced with the computer's ability to boil vast amounts of data into a coherent answer and they want to harness this power to solve problems about truly organic creatures.

Peter J. Bentley's new book, Digital Biology is a lively tour through some of the research that joins both of these worlds. It's a quickly paced, colorful examination of how computer scientists and biologists can share metaphors like "the immune system" or "growth." If both groups sit down and compare metaphors, computer scientists may learn something about building robust, self-healing, self-reproducing software from looking at carbon- based creatures while biologists will learn something about creatures by studying them with silicon-based software software.

The book is aimed at the same market that embraced the meme of "Chaos" through reading James Gleick's book. The book is light on equations and heavy on showmanship. In many cases, this is more than satisfying. One description of digital flocks of birds describes how three simple rules can keep the birds floating and swarming with all of the coordinated rolling and swooping. There's no need to invoke numbers or distance measurements to convey what's happening.

At other times, the examples can be so tantalizing that the lack of depth can be a bit frustrating. Bentley promises "The number of different applications that we have successfully used evolution for is immense." To explain this, he offers an example of a coffee table designed by a computer program mixing, matching and cross-breeding varieties. After each generation, the computer cuts some desks apart, creates new combinations and then uses an equation to find the most fit and desirable desks. Eventually, a reasonable candidate emerges. After explaining that genetic algorithms may find patterns of credit card fraud and help us find better jet turbine blades, there's no space to tell us the finer details. We do learn that stunning results can emerge when computer programmers mix the three principles of inheritance, variation and selection. But no book can include everything.

While the book is aimed at a broad market, it does not come with many of the traditional flourishes of journalism. Bentley is research fellow at University College in London, not a newspaper hack who churns out stories for a living. So when he introduces other researchers and colleagues, he doesn't bother with dressing them up with details about their homes, their wives, or the usual chestnuts journalists offer in the hope of humanizing the subjects. The book focuses on the ideas and metaphors themselves and doesn't bother with the window dressing. The names are just incidental markers to give credit and a pointer for further research. Scientists will love the lack of distraction, but casual readers looking for colorful anecdotes about the wacky geniuses in labcoats will need to look elsewhere.

The book, as expected, is generally enthusiastic and heavily invested in the field. Software modeled on biological systems, we are told, will, "detect crime for us, identify faults, ... design new products for us, create art, and compose music."

Despite this partisan flavor, the book shines in the few paragraphs where Bentley pauses to discuss some of the limitations of the systems. "We cannot prove that evolution will find us a good solution-- but it almost invariably does. And we certainly cannot predict that solutions that evolution generates," he notes as a caveat to everyone planning to use genetic programming to solve world peace.

At one point, he discusses one of the principle criticisms of the entire area. After describing flourishing digital forests filled with fractal ferns, problem solving viruses, and swooping swarms of evolving birds and insects, he pauses and offers this quote from another biologist: "Where's the experiment?" He notes that most of these creatures are flights of our imagination untested in the lab against real ferns, viruses or birds. Nor is there any real way to test a fern hypothesis. The digital versions look real, but there's little gritty lab work to establish them as true metaphors for sussing out the secret laws of nature. Is looking real enough? Can you measure verisimilitude? Do any traditional experiments measure anything better than the quality of a simulacrum? Is appearance enough or is it only skin deep? After a pause, though, the book is on to more talk of big payoff and grand promises.

In its heart, the book is more a document that shows evolution of problem solving techniques. If you want to get the sales pitch from the computational biology world, you can turn to this book. When there were no machines, scientists used symbols, algebra, calculus and other mathematics to describe the world. Biologists have long employed differential equations to describe the booms and bust in ecologies of predators and prey. Now that we have computers capable of billions of operations in a second, we don't need the old school of mathematics to provide a closed-form solution. The computers can just simulate the world itself. There's no need to struggle for a set of equations that is both easy-to-solve and appropriate. We can just use little worlds of sims creatures, sim fronds, sim viruses, and sim antibodies.

Bentley's book is an ideal way to learn just how and why some biologists are absolute enraptured with the new powers discovered by these computer simulations of genetics, growth, flocking and other natural phenomenon. These models don't offer the kind of concrete certainty of mathematical models, but there's no denying that something is somehow there. Is it as much a breakthrough as Bentley believes? Well, maybe you the reader can create a genetic experiment to cross fertilize the ideas from the book with the ideas in your experience. After a few generations of thought, perhaps a few generations of beer, an answer might evolve.

Peter Wayner is the author of Free for All, a book on the open source software movement and Disappearing Cryptography , the second edition of a book on steganography expected to appear later this spring. He is also the author of several articles on simulation including studies of studies of the relationship between sex and AIDS , segregation , and the length of baseball games. (Each of these links includes a Java applet so you can run the simulator from your browser.) You can purchase Digital Biology from Fatbrain. Want to see your own review here? Just read the book review guidelines, then use Slashdot's handy submission form.

13 of 137 comments (clear)

  1. Biologists and Psychologists Abuse this... by Ieshan · · Score: 4, Insightful

    To the worst extent possible.

    My psych professor explained our language lecture using layman's computer terminology, instead of psychology. I wanted to strangle him the entire time. "So... you've got this memory stuff... and it get accessed - that is - processed, by this other bit over here, right, this area of the brain... let's just call that the "software"."

    It was enough to make any techie of any note sick. He actually used Microsoft as a language. Talk about wanting to shoot someone.

    But what can we do? Everyone thinks they're a programmer or a techie these days, and everyone thinks that because kids use IM they must have some other association with the grey box.

    Sorry fellers, that's wrong. Most kids today don't know jack about computing, much less are able to relate better when you babble incessantly about things in your half-tech, half-psychologist manner. Stick to the psychology or the biology, instead of using computer terms to explain simple concepts. It's just more confusing and more hellish. :(

    1. Re:Biologists and Psychologists Abuse this... by Anonymous Coward · · Score: 5, Insightful

      As a neuroscientist and former CS major in college (and long time Slashdot reader) I can also assert that programmers abuse biology metaphors just as badly!

      I'm tired of the comprarison of viruses to computer viruses, as well as DNA to computer code. Everytime an article on neural/silicon interactions comes on - here come the stupid Neuromancer "jacking-in" references! Every time a genetic engineering article comes here, people whip out "Jurassic Park" and "Chaos theory" to explain why they don't consider GM a good idea!
      Mixing some computer and biological metaphors on a very BASE level has its uses, but people on both sides all too often become overly enamoured with these simple comparisons and forget the very REAL and often subtle differences that invalidate the metaphors.

      A lot of coders I've met need to learn as much REAL (not popular) biology as the biologists you are complaining about need to learn about computers! Basically - I thought your comment was more than a bit one-sided and somewhat condescending - knowing alot about bits, pointers and registers doesn't make you any more qualified to mix metaphors than knowing alot about neurons, genes, and molecules does!

      Sincerely,
      Kevin Christie
      Neuroscience Program
      University of Illinois at Urbana-Champaign
      crispiewm@hotmail.com

    2. Re:Biologists and Psychologists Abuse this... by Pentagram · · Score: 4, Insightful

      I'm tired of the comprarison of viruses to computer viruses, as well as DNA to computer code.

      Excuse me? Surely both examples you give are excellent analogies of each other. Viruses parasitically use the machinery of their hosts to spread themselves... and so do computer viruses (well, worms at least.)

      And DNA is a digital series of instructions that are interpreted to express something... and so is computer code. Has anyone proved you can build a Turing machine in DNA yet? Admittedly, DNA is processed in a rather more analogue fashion than most computer code, but as an an analogy, it's better than most; (for example) the old one about breaking computer systems/ breaking into a house.

    3. Re:Biologists and Psychologists Abuse this... by crush · · Score: 3, Insightful

      Surely both examples you give are excellent analogies of each other.Viruses parasitically use the machinery of their hosts to spread themselves... and so do computer viruses (well, worms at least.)

      Computer viruses do not physically dis-assemble the host computer (or its OS), chopping it up into pieces that are re-assembled to from new infections computer viruses. A big difference.

      And DNA is a digital series of instructions that are interpreted to express something... and so is computer code.

      Digital series indeed!! DNA is more like a recipe as S.J.Gould and others never tire of pointing out (evidently for a good reason). If it were a program it would be the buggiest, crappiest program that had been maintained for years with different compatability layers added to it. If it were a program it would be as though COBOL had been kept and had new libraries added to it, some of which worked sort-of, and others were completely b0rken.

      The point of this is that the analogies/metaphors/comparisons are not really useful beyond a simple level. Interesting analogies or metaphors are ones that reveal _unexpected_ details about the analogised subject. The code/DNA one does not. It is just two cool things lumped together with superficial similarity.

  2. Information wants to be Anthropomorphized... by Bonker · · Score: 3, Insightful

    Humans have a tendancy to cast biological, and even human, behaviors on anything that is outside their ken.

    Case in point. When I was helping my mother restore her computer after she was infected with Code Red, she was infuriated at the worm. While she is a computer professional, she is not a coder and has no understanding of... say... how machine code executes a loop or a goto. She talked about Code Red as if it really was a living thing despite the fact that she knew better. One of the things she said that stuck in my head was 'Why would it do that to me?'

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  3. Re:Warning by Gannoc · · Score: 3, Insightful
    can you simply ignore the evolution going on from Commodore 64 to Apple IIe to Mac to Windows box

    Unless, say, an Apple IIe in the wild mated and birthed a mutant Apple IIgs, which due to advantages in the environment lived to mate more and more with other machines, then thats not evolution. Just because something is advancing doesn't mean its "evolution".

  4. Re:Warning by boaworm · · Score: 3, Interesting

    For those who (inexplicably, through brainwashing or other) don't believe that evolution happens, computers (and their software) provide an unequaled example of evolution in progress

    Indeed. For those familiar with Artificial Intelligence, Genetic Algorithms and Genetic Programming, this should already be familiar.. but to enlighten the rest :-)

    When talking about AI you have to make a differentiation between the "body" and the "brain". In a computer simlulation you can say that the simulation environment is the body and the "genome" (phenotype) is the brain. Intelligence does not lie in either, but in the cooperation between them. Rather simple.. how much is your brain worth without eyes, arms, legs, nerves etc ? And the other way around.. what to do with your body if you cannot process the data.

    So, back to the reflection on the comment above, most people tend to say that humans evolve through the brain, while it is more true to say that the brain and the body coevolve. The same goes for computers, both software and hardware coevolves, keeps getting better and matching each other.

    The interesting part here is that if we can understand the body (not that hard, just molecular biology and stuff), then we have one of two keys to human intelligence. That is why biology and computer interaction is so interesting, if we can simulate biology (body) on a computer (body), then we have an increased ability to learn about the brain. A few months ago, an Israeli company successfully performed calculations on human cells. This is the reversed way, using biology as the "body" and computer algorithms as the "brain". Very interesting results, and very promising. This generation or the next should have a fairly good chance of screwing up this planet totally :-)

    --
    Probable impossibilities are to be preferred to improbable possibilities.
    Aristotele
  5. Please do not feed the hypocrites by PsiPsiStar · · Score: 3, Insightful

    I love this comment

    People with open minds may want to avoid this book

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    It's the end of my comment as I know it and I feel fine.
  6. Here's another great link by westfirst · · Score: 4, Insightful

    http://www.digitalbiology.com/

    Plenty of good stuff. Anyone have other good links?

    1. Re:Here's another great link by payslee · · Score: 3, Insightful

      This one is my favorite. You can watch the flocking boids, and it explains flocking algorithms very clearly and easily.

      Plus, it's got links to about 50 other really interesting biological modeling and application sites.

      --
      Doing my part to piss off the religious right.
  7. Be careful not to take this too far. by Yet+Another+Smith · · Score: 4, Insightful

    I'm a little worried that if this gets too 'faddy' that people could start looking for biological metaphors and ignore other eqeually effective, or perhaps more effective solutions.

    For example, from the review above:

    genetic algorithms may find patterns of credit card fraud and help us find better jet turbine blades

    The genetic algorithm is a great algorithm for optimization problems. However, its not significantly more effective than the simulated annealing algorithm or the less-known controlled random search algorithm.

    Each has its advantages and disadvantages, but getting too caught up in the metaphors these algorithms and techniques are based on will unnecessarily shackle your thinking. Of course, the opposite is also true. Refusing to embrace metaphors at all will leave you without the insights that we use metaphors to see, so don't take me too seriously :).

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    if ($it != $onething) {$it = $another;}
  8. Re:Warning : Ignorance in the name of piety by gregor_b_dramkin · · Score: 3, Insightful

    I would probably not respond to the above and disregard it if it were not for a recent Sci Am article that showed ~40% of Americans believe in creationism over evolution.

    I cannot understand how seemingly intelligent people can ignore overwhelming scientific evidence. Evolution is the most widely explanation for how we came to be. I do not see any inconsistencies with the Genesis *metaphor* for the creation of life. The Bible is written by humans, not God. They may have had divine inspiration, but it was not God's pen in the inkwell. Why do you think there are four "Gospel according to XXXX"?

    BTW, God is omniscient. Don't you think He can understand and use a metaphor?

    Of all the types of ignorance in the world. Those that perpetuated under the guise of religion are the most virulent and dangerous.

    --
    You can never equivocate too much.
  9. Biology vs. Comp. Sci. by Mannerism · · Score: 3, Insightful

    This area has always interested me because I did my undergraduate degree in molecular biology, and my professional career has been in software engineering.

    The first thing that strikes me when biology and computer science are brought together is that although we try to apply principles of the former to the latter, we really have a much firmer grasp of computer science than we do of biology. What we're really doing, I think, is taking some theories and concepts from biology -- evolution and immunology seem to be the big ones -- and adapting those theories to suit digital computers; we're not modelling life per se. It's important to remember, too, that although we can model evolutionary processes like variation and selection in a computer system and produce the anticipated results, we can't thereby prove that evolution applies to life. (I happen to believe that it does, but I have to admit that we have yet to irrefutably prove it). All we're doing is nicely illustrating the theory.

    Someone mentioned earlier that everyone claims to be some sort of computer expert these days, and that biologists and psychologists routinely misapply computer concepts. From my perspective, the reverse is true. There seems to be a misconception that biology is straightforward and well-understood, and I just don't know where that comes from. I'm sure I'm not the only biologist who grimaces when "virus" is used to describe software. And the most gaping errors in science fiction always seem to be ones of biology. Computer scientists use words like "genotype" and "phenotype", but genetic algorithms seem to me to be so far removed from the actual complexities of gene expression as to be at best distant cousins. It's more a matter of biology lending ideas and inspiration to computer science than it is some direct translation of life processes to software processes.