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> imagine the code arose originally by random chance If you said this in any other context, it would sound laughably ludicrous. Imagine billions of lines of co

> imagine the code arose originally by random chance If you said this in any other context, it would sound laughably ludicrous. Imagine billions of lines of code for an incredibly advanced, complex and self-replicating system appearing out of the thin air (over 2 bil. yrs) by mere chance. Even with the long time period, it sounds facetious, prima facie. For some reason people decide to switch off their common sense and rationality when it comes to this.

gipp 10y ago
You don't understand how evolution works (not that the parent you're responding to stated it well). It is most certainly not "random chance". Frankly I'm surprised to see that kind of sentiment coming out of such a CS-heavy audience, since genetic algorithms demonstrably work, and function on the same mathematical principles minus the biological substrate.
- tps5 10y ago
  Don't basically all genetic algorithms rely on "random chance," or some simulation of random chance, to simulate a mutation rate? And haven't biologists, in recent years, emphasized the degree to which evolution relies on mutations and genetic drift? That was my understanding of the way the field has been going, anyway. Saying that evolution as a whole is just "random chance" seems reductionist, but randomness does appear to be involved.
  - gipp 10y ago
    Certainly randomness is _involved_, but it is randomness governed by a decidedly non-random fitness function. Without fitness there is no evolution. The problem arises because when biologists, statisticians etc say "random process," they mean something very specific that can actually contain many different kinds of mathematical structure, but your average layman hears that term to mean "¯\_(ツ)_/¯"
  - semi-extrinsic 10y ago
    Consider throwing 20 dice. It is certainly a random process. And we know the odds for throwing 20 sixes is about one to 30 000 trillion, so you'd have to keep throwing dice for about as long as the Earth has existed to get that result. But if you start throwing the dice and you keep all the sixes you get along the way, Yahtzee-style, we expect you'll have 20 sixes in about 25-30 throws. In the latter case, external selection has turned an incredibly implausible result into a certainty.
    - tps5 10y ago
      I don't agree with this analogy though. Who's to say if life evolved on earth all over again, we'd end up in the exact same place? Sure, some of the same adaptations would re-emerge. But some might not. And there might be extraneous mutations that had no effect on fitness at all but drastically changed the appearance of some subset of species. If we assume true randomness is involved then we assume evolution itself is going to deliver non-deterministic results, don't we? To put it in terms of genetic algorithms, we could run through N generations M different times and get different results each time. To me that makes it seem like saying "randomness is an important aspect of evolution" isn't so far from the mark.
      - gipp 10y ago
        We absolutely wouldn't end up in the same place, simply because the state space of possible organisms and environments is astronomically larger than the space of possible dice rolls (his metaphor isn't perfect and I'm already straining it here). But we would be almost guaranteed to end up with organisms that have similar levels of complexity. Again, randomness is an important part of evolution, but there are also necessary deterministic aspects of it that make the "blind watchmaker" type arguments that started this discussion irrelevant.
        PetoU 10y ago
        according to https://en.m.wikipedia.org/wiki/Evolution_of_biological_complexity https://en.m.wikipedia.org/wiki/Evolution_of_biological_comp... Complexity argument is not valid. It's debatable at least. AFAIK it's part of the bigger discussion whether evolution has direction.
maverick_iceman 10y ago
Natural selection is very different from random chance.

gipp 10y ago

You don't understand how evolution works (not that the parent you're responding to stated it well). It is most certainly not "random chance". Frankly I'm surprised to see that kind of sentiment coming out of such a CS-heavy audience, since genetic algorithms demonstrably work, and function on the same mathematical principles minus the biological substrate.

tps5 10y ago
Don't basically all genetic algorithms rely on "random chance," or some simulation of random chance, to simulate a mutation rate? And haven't biologists, in recent years, emphasized the degree to which evolution relies on mutations and genetic drift? That was my understanding of the way the field has been going, anyway. Saying that evolution as a whole is just "random chance" seems reductionist, but randomness does appear to be involved.
- gipp 10y ago
  Certainly randomness is _involved_, but it is randomness governed by a decidedly non-random fitness function. Without fitness there is no evolution. The problem arises because when biologists, statisticians etc say "random process," they mean something very specific that can actually contain many different kinds of mathematical structure, but your average layman hears that term to mean "¯\_(ツ)_/¯"
- semi-extrinsic 10y ago
  Consider throwing 20 dice. It is certainly a random process. And we know the odds for throwing 20 sixes is about one to 30 000 trillion, so you'd have to keep throwing dice for about as long as the Earth has existed to get that result. But if you start throwing the dice and you keep all the sixes you get along the way, Yahtzee-style, we expect you'll have 20 sixes in about 25-30 throws. In the latter case, external selection has turned an incredibly implausible result into a certainty.
  - tps5 10y ago
    I don't agree with this analogy though. Who's to say if life evolved on earth all over again, we'd end up in the exact same place? Sure, some of the same adaptations would re-emerge. But some might not. And there might be extraneous mutations that had no effect on fitness at all but drastically changed the appearance of some subset of species. If we assume true randomness is involved then we assume evolution itself is going to deliver non-deterministic results, don't we? To put it in terms of genetic algorithms, we could run through N generations M different times and get different results each time. To me that makes it seem like saying "randomness is an important aspect of evolution" isn't so far from the mark.
    - gipp 10y ago
      We absolutely wouldn't end up in the same place, simply because the state space of possible organisms and environments is astronomically larger than the space of possible dice rolls (his metaphor isn't perfect and I'm already straining it here). But we would be almost guaranteed to end up with organisms that have similar levels of complexity. Again, randomness is an important part of evolution, but there are also necessary deterministic aspects of it that make the "blind watchmaker" type arguments that started this discussion irrelevant.
      - PetoU 10y ago
        according to https://en.m.wikipedia.org/wiki/Evolution_of_biological_complexity https://en.m.wikipedia.org/wiki/Evolution_of_biological_comp... Complexity argument is not valid. It's debatable at least. AFAIK it's part of the bigger discussion whether evolution has direction.

maverick_iceman 10y ago

Natural selection is very different from random chance.