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gimmic for zerobot evolution

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ikke:
I was thinking about the way DB behaves around zerobot evolution an the emergence and propagation of replication. It occurred to me that the zerobot as it currently has been defined already has a fundamental characteristic of life that greatly impacts propagation of replicating genes: self containment. Two randomly evolved genes cannot bond head to tail when in physical contact, nor can a gene split up in two autonomous parts. Imagine a zerobot developing some sort of replicating mechanism without this auto containment: it would pass on replication to whatever other bots it would come into contact with. Inversely, the population could grow without replication. In DB this could be modelled by introducing a few items: a close to represent the boundaries of the selfcontainment, and the rule that bonding or breaking cannot occur before the first close. Combined with probabilities of bonding and breaking this should push back the start of DB simulation back further ito the aminoacid soup

bacillus:
Of the part I can currently understand, I do agree that it is wierd having the zerobots "evolve" bodies before they become replicators. I'll come back when I'm in an environment that allows me to digest info.

shvarz:
It's a good point and there is nothing we can do about this - DB is based on the concept of bots. It never was specifically design to ask the question of emergence of life - from the beginning it was always about evolution of existing life. The "zerobot" approach is relatively new here. It was brought in just as a fun challenge.

BTW, you can treat each bot at that stage as a puddle of water that is full of pre-biotic material. In that case the evolved replicator (a particular set of DNA commands within that pe-biotic material) does indeed replicate all other stuff along with itself.  So it's not self-contained. The abstract nature of bots can be interpreted in many different ways

EricL:
I'll just point out that due to technical limitations in the simulator, evo sims of any sort were basically a joke until perhaps 2 years ago, which is about when the zerobot concept caught on.  For various reasons not the least of which were limitations on the number of mutations details that could amass before bad stuff happened (yes, these issues existed in the 2.36 code base) no one was even capable of running long term evo sims until I fixed those bugs.  So, no one was able to explore the issues related to the effect of cummulative mutations on hand authored code or to understand that people just don't author code in the same way nature does.

We talk about conspecs and species recognition and canibots and such as if our concept of those things have some relationship to evo bots but they don't.  No DNA has ever evolved enough logic to have the ability to care about other copies of itself much less recognize them.  Those terms are meaningless to date w.r.t. evo sims.

Zerobot evo sims in my mind arn't about the origination of life.  Rather IMHO, they are the only kind of evo sim that is worth doing.  Any evo sim that begins with a hand coded bot of any complexity is bascially akin to shooting gamma rays at a space shuttle.   Your taking something man made and artificial, built in a manner nature didn't create and would never use and simply using mutations to degrade it, comparing which copies degrade the slowest and acting surprised when some degraded copy malfunctions in an interesting manner.  Hand authorred bots were not designed to be mutation resistant, they have no evolution history.  They didn't come from anywhere and they arn't going anywhere in an evolutionary sense.  They're a built thing, not an evolved thing and as such you can't expect them to go anywhere but "down" when you start the evolution clock by enabling mutations.  They're DNA occupies an unreaslitic peak in the fitness landscape, one unreachable by evolution.

Of course it takes a few tens of millions of cycles for this to become apparent, which is why people still try running evo sims with hand coded bots and think something worthy is happening when their delicate hand-authored conspec recognition or body management code breaks and they get so-called cannibots or cancerious bots.  IMHO, there's nothing worthy or interesting or surprising about that.  The breaking of hand coded conspec code is not evolution preferring cannibalism.  Its not evolution at all.  It's just the space shuttle failing in an interesting way as it falls off it's impossible peak in the fitness landscape.

Numsgil:
I am going to disagree and say hand authored bots can give interesting results.  Let's assume that the bot is at the top of its fitness landscape.  It is simply the most perfect bot ever written by Man.  With a sufficiently large population, and low enough mutation rates, you should be able to run a sim of those little buggers for millions of years and have them not change, which is sure an interesting result.

The problem is that we have yet to devise a long term environment that exactly mimics the conditions of a F1 contest, so features that are good in an F1 contest just aren't good in a sparse and safe long term evo sim.  When a bot develops cannibalism, or whatever, it is evolving.  That it comes up so frequently is a sure sign of that.  Bots that don't remember how to feed, for instance, die rather quickly.  We may not like the sort of mutations that break behavior we built, but it's a valid evolutionary strategy that makes the bot more fit iff it catches on and everyone does it.

Destructive adaptations aren't the only things I've seen with hand authored bots.  I have also seen alga minimalis evolve to wiggle instead of turn, which caused it to be much harder to eat.  That mutation quickly was the only one left, and most of my other bots died from starvation.  Zerobots are fun to run, not because they're the only things that are evolutionary, but because they allow us to look at something that is purely evolutionary.

Anyway, to the topic at hand, I think Eric's right and the technical limitations of the simulator are going to be the primary limiting factor.  Reproduction is sort of magical like it is because that's the easiest way.

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