Monkeys, Weasels and Shakespeare, Explained


In a previous article, I described how 101 trained monkeys could come up with a line from a Shakespeare play.   And in a subsequent article, I simulated the process with a small computer program.   In this article, I would like to explain why this process is important to the theory of evolution.

The idea for simulating this process came from a similar computer program that Richard Dawkins wrote way back in the days of the Apple II.   Since the line of Shakespeare mentions weasels,  all of the different incarnations of this program are affectionately called weasel programs.

My contribution in this series of articles was to first propose the process as something being carried out by 101 monkeys instead of a computer program.  I think it is easier to relate to the process through the monkey scenario.   Before I discuss the connection that monkeys and Shakespeare have with evolution, I want to highlight some very important points in the monkey scenario.  If you don’t remember what the monkeys are doing, reread my first article.

Mindless Process
Firstly, it is important that none of the monkeys can read or write in English or any other language.   Each of the 100 Copy Room monkeys and Levi are only trained to do their tasks on the symbols on the index cards.  They have no idea about the meaning or intent of each symbol, the string of symbols or the intent of the overall process.   None of that is required.  They simply do their task because we reward them with cookies after they are done.   If the monkeys do have other cognitive skills, they are not required for these processes to work.

Another important point is that Levi doesn’t know who or what is in the Copy Room and the Copy Room monkeys don’t know that Levi is next door in the Counting Room.    They just do their thing when the cards appear through the window.   That means you could replace the Counting Room monkeys with a computer  program and Levi would not see any difference.   Or you could replace Levi with a computer program and the Counting Room monkeys would not notice any difference.  (And naturally, you could replace the whole thing with a computer program and save yourself a lot of cookies.)

Information Is Transferred, not Created
he perceptive reader should immediately recognize that nothing new is actually being created by the monkeys.    All that is accomplished is that the string of symbols carved on Levi’s desk ends up on the last index card.   So what we are looking at is some kind of transference of something from desk to index card through a particularly cumbersome  process requiring monkeys who are working the process to get cookies.   The process is so bizarre that it requires a huge waste of time and index cards and only manages to achieve its goal incrementally through a lot of trial and error.

No Goal Orientation
What might not be so obvious is that there is nothing really goal oriented about the various pieces of the process at all.   Copy monkeys simply copy, and Levi simply counts, chooses the card with the lowest number and stops when the number is zero.   (Well ok, the monkeys’ goal is to get cookies).   So although the process reaches a goal, there is nothing that can be seen as an intrinsic intent or desire to reach a goal.  To demonstrate that, suppose while Levi is waiting for the 10,000 cards to emerge, we distract him with a cookie and switch around some of the symbols carved in his desk.    Because Levi has poor short-term memory, the process would tend to wander around mindlessly tracking the changes.

Randomness As a Creative Process
Another thing that might not be so obvious is that the process would not work if the Copy Room monkeys were not so careless.    Since we seed the process with the first index card that says, “levi”, all a perfect Copy Room could produce would be 10,000 index cards that say “levi”.   And no matter how many times we sent a “levi” card back in, all we would get back out is 10,000 “levi” cards.   It’s the mistakes the Copy Room monkeys make that provide a kind of raw creative material upon which Levi acts unwittingly.

Accumulating the Good Stuff
And finally, what makes the process work so quickly is that each time Levi picks the best index card, he is preserving all the best choices from all the previous cycles and discarding all the bad ones.   In other words, each cycle starts with the best results from the previous cycle.   Therefore, all the best arrangements of symbols from cycle to cycle accumulate over the cycles until the weasel string is reached.    If Levi just chose an index card from the 10,000 each time arbitrarily, the process would continue forever never achieving anything.

Oh Yeah.  Evolution.
Although this is a simplified process, all the concepts I discussed here are important for understanding the process of Darwinian evolution.     The string of symbols represents the DNA of an organism.    And the Copy Room represents what happens when DNA is replicated during reproduction.    DNA is a molecule that makes copies of itself imperfectly.    So when each offspring of an organism is conceived, it receives a slightly different DNA sequence than its parent’s and its siblings.    The differences are called mutations and they are made up of deletions, substitutions, and additions of genetic material.    These mutations simply happen because of the nature of the DNA molecule with no regard to its consequences down the line.

Then all these slightly different siblings go off into the world.    Their slight differences given them slight advantages or disadvantages when it comes to surviving to their own age of reproduction.   And those that do manage to reproduce pass along these favorable mutations to the next generation, along with the next set of mutations.   In that way, the good stuff accumulates and the bad stuff never gets passed on.

So Levi is like the challenge of the environment in which these offspring organisms will attempt to survive.   Levi’s criteria for selecting an index card from the 10,000 “offspring” cards, is very simple and one-dimensional.    Whereas in nature, the selection for criteria for who gets to reproduce is hugely complex and multidimensional.  And the number of ways that variations can confer a survival advantage in any given environment is large.  So there is more than one right answer for a favorable variation.   And more than one offspring with its particular favorable variations may survive.

Similarly, it is the challenging environment that ends up unwittingly exploiting the creative opportunities that come from the random mutations.  If DNA made perfect copies, there would be no variations to exploit, and all organisms would stay the same forever.  And finally, during the evolution process over many generations, the environment might be changing as well, so the process is unwittingly tracking these changes just like our weasel process does when we keep changing the symbols carved on the desk.

Finally, what is no so obvious is that although novel life forms end up emerging from this process, they are still only reflections of the environment around them.   What ends up occurring is that the genome ends up becoming an expression of that environment.   Or you might say that information about the environment ends up being transferred into the genome in small increments over generation after generation.

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2 thoughts on “Monkeys, Weasels and Shakespeare, Explained

  1. Pingback: On Monkeys and Shakespeare, Preliminary Results | Mobile Terra Sistema

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