Randomness is not necessary for evolution

by seattleniceguy 20 Replies latest watchtower beliefs

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  seattleniceguy

  Continuing this theme of evolution and randomness that has been going on this week, I wanted to address a common pitful for the would-be evolutionary student. Often, a person will remark, "I see how the theory works, but I just can't believe it all came about by chance." If you're such a person, you'll be happy to know that evolution does not require chance at all.

  Evolution is a two-step process: 1) Make some changes. 2) Select out the unfit ones. The force that selects out the unfit ones, as we all know, is the natural selection of the cold, hard world, with its limited resources and harsh environmens. But the other force, the one that provides the genetic diversity, is typically less understood. Chance, or randomness, is not a requirement at all. The only requirement is that offspring be different from their parents. This could happen through totally deterministic means ("deterministic" is the opposite of "random"), and evolution would still work just fine.

  There are three things required for evolution. They are:

  • Replication - the ability for something to make a (near) copy of itself
  • Mutation - essentially, the ability for the copies not to be exact duplicates
  • Heritability - the ability to receive traits passed down by your parents

  The middle bullet point represents genetic change between parent and offspring. It can come from any means: random forces, deterministic forces, God actually tweaking the genes with his forefinger - it doesn't matter. Once these three things are present, evolution occurs automatically. It is impossible at this point for it not to occur.

  The main point to all of this is that evolution doesn't care a lick whether or not the genetic change it works on is random. Randomness is not necessary for evolution. In reality, it may be a fundamental part of the universe, and evolution is fine with that. But in the end it doesn't matter. So the next time you catch yourself or someone you love saying, "But how could it come about by chance?" stop and think about the actual mechanisms of evolution.

  SNG
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  Daunt

  Very nice point Seatleniceguy. Many people base their whole abstinence from evolution from this "chance" factor that seems to be there, shunning themselves from an endless array of knowledge from this subject and possibily even shunning away an endless amount of other subjects because their faith depends on this evolution being false.
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  tetrapod.sapien

  SNG,

  so true, good point.

  and actually, it's not even fair to say that the mutation mechanism of evolution by natural selection is truly random either. for all intents and purposes, it seems random, and is random enough, for biological diversity. but many of the environmental pressures that cause mutations in embryonic development are the same, or very similar from organism to organism, or even across some populations that are not in the throws of big ecological changes in their environment. this is because more often than not, they are in the same environmental pressure situation as their ancestors, and behaving very similarly. and so, we have gradualism and a fine grained genetic space.
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  Daunt

  Another thing to add to this, is that evolution and the origin of the universe is essentially cause and effect. Something happens and it effects another event to happen. This is just like evolution. The floating bacteria from the young earth ran out of sludge to replicate themselves with, so they found other ways to sustain themselves through different mutations. The calcium in their early home could have poisoned them, so what did a particular group of cells do? they used that calcium to their advantage by taking in small parts of it to form a skeletal structure through many trial and error. This has been going on from Dinosaurs having wings to the creation of human beings. Except from the Big bang and the spark that gave earth this susceptibility towards life itself, it doesn't seem random at all.
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  Pole

  SNG,

  Be careful! You are making a controversioal philosophical assumption!!! As I pointed out on the other thread it's good to look at the history of the notion of randomness in natural sciences before drawing ultimate conlusions. Also look at Hume-Kant disagreement over cause-effect metaphysics in this respect.

  I believe that we have to allow for some notion of randomness if we want to make coherent bio-physical models. Randomnes + deterministic rules = probability distributions.

  I could argue there is no "infinity" in nature. But the concept is extremely useful and we don't know if it's actually not inherent to certain processes. Certain mathematical functions that reliy on infinity applied to physical phenomena make almost perfect sense.

  But - as I said earlier I agree that the creationst argument that evolution is totally random and thus unlikely is completely flawed. Sometimes "random" functions applied to natural processes indicate 99.99999% probability that something happens. Of course the creationist still has a 0.0000001% chance of being right.

  Pole
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  seattleniceguy

  Pole,

  I wasn't saying for a fact that there is no randomness in the universe (at least not on this thread ). I was just pointing out that evolution works regardless of whether or not there is randomness. For example, consider the myriad computer simulations of evolution. Evolution proceeds in spite of the fact that there is no randomness in the system.

  SNG
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  Pole

  SNG,
  ::I wasn't saying for a fact that there is no randomness in the universe (at least not on this thread ). I was just pointing out that evolution works regardless of whether or not there is randomness.
  OK. I agree. Although randomness helps explain things.
  ::For example, consider the myriad computer simulations of evolution. Evolution proceeds in spite of the fact that there is no randomness in the system.
  I'm not sure what you mean? A simulation which doesn't allow for randomness would be totally bogus for me. that would mean every time you run your primordial soup application, you get exactly the same number of amino acid particles in exactly the same configuration. Or am I missing something?
  
  Pole
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  tetrapod.sapien

  I'm not sure what you mean? A simulation which doesn't allow for randomness would be totally bogus for me. that would mean every time you run your primordial soup application, you get exactly the same number of amino acid particles in exactly the same configuration. Or am I missing something?

  no. my $0.02-

  the program, like AVIDA for example, uses so-called "randomness". it never produces the same thing twice, or that we can tell anyways for all intents and purposes. but, the computer itself is not random entity, or processing environment.
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  rem

  I used to run Tierra... are there some newer/better evolution simulation programs out there now? I always found it amazing how a simple algorithm and some random input can create programs so complex that humans cannot even decypher, yet reproduce and form "strategies" for survival.
  
  rem
• 

  tetrapod.sapien

  I used to run Tierra... are there some newer/better evolution simulation programs out there now? I always found it amazing how a simple algorithm and some random input can create programs so complex that humans cannot even decypher, yet reproduce and form "strategies" for survival.

  rem,

  this is actually how i "fell out of The Truth". as a wit, i was just a linux geek, running my home made 8 node cluster. i was looking for opensource programs that i could tweak to run on my cluster, and i came across AVIDA. and that's why i'm partial to it. it's opensource, and so i would say that it is really a good program to run, and modern. the feb 2005 issue of discover mag had a cover article on it. and, so, that's what got me thinking about biology and evolution, and that's what got me doubting the truth.

  my answer to your question with a little personalization thrown in for fun.

  TS