Messages

46

Suggestions / Muscles, Fat, and Chloroplasts

« on: October 25, 2006, 07:43:10 AM »

I like that idea (it occurred to me too as I was reading above only to realise Numsigil got there earlier and posted it before me  ), it is a little counter-intuitive (you'd think a fatter bot would be larger) so perhaps "fat" isn't the best name for it?

In real life muscle has a high cost to form but it is actually more efficient to retrieve stored energy from muscle than from fat once you have already invested in the muscle. So to add another suggestion to the melange: Currently the maximum rate of body increase/decrease is capped. By changing it slightly to make the cap dependent on the "input" substance instead of equivalent nrg you can make muscle slow to form but quick to break down. Like so: 10 nrg > 1 muscle, 1 muscle > 10 nrg, with a cap of 100 nrg or 100 muscle converted per cycle. So the maximum muscle that can be formed each cycle would be 10 muscle, but in any cycle 1000 nrg can be liberated from muscle. Obviously the numbers could do with a little tuning but I hope they illustrate my point.

47

Suggestions / Repopulating/Refreshing non-Veggies

« on: October 24, 2006, 10:55:20 AM »

Ooh, that's a good description of the problem, it makes sense. That has just brought a little more about fitness, genetics and mutations out of the heading of "accepted as fact" into "understood".

48

Suggestions / Muscles, Fat, and Chloroplasts

« on: October 24, 2006, 10:11:32 AM »

Is there any real need for "fat"? I can't see an advantage to it. In fact all I can see are disadvantages - the cost of the instructions to store and retrieve nrg from fat, the increased size = increased drag, and a time lag between needing nrg and converting it back. The only good thing about "body" was the increased shot power, and that's been proposed to be the domain of muscle now.

The near-perfect storage system for nrg currently is nrg, that has no upkeep cost and it costs nothing to make available for use.

Might it make more sense to not use fat, but instead make the bot's base size dependent on the nrg it has?

While I like the idea of muscle costing to upkeep, that could kill a bot quite easily. Perhaps something like 1% of the bot's muscle is converted to nrg every cycle if the *.muscle is above 100, so the bot has to keep maintaining it.

49

Suggestions / What should vegs not be allowed to do?

« on: October 23, 2006, 10:11:58 AM »

Why not create a setting (tickbox, whatever) that says that a bot is a restricted veggy?

I don't think the idea of restricting vegetables with regard to eyes etc. is a good thing, the more freedom there is the more interesting the simulation becomes after all!

But if the user can specify a bot to be a "restricted" vegetable then it would allow us to run much larger sims with lower overheads, and not interfere with the more interesting vegetables possible.

In fact, nearly all veggies I use in my less exotic sims are Alga Minimalis. Is there some way of making this more efficient? All (unmutated) AM veggies act the same way, so how about creating a "default" veggy bot that acts like AM but is not handled by the DNA script system? Could that shave a few microseconds off a cycle? Just throwing wild ideas into the teeth of the wind here.

50

Evolution and Internet Sharing Sims / Mutation Sims

« on: October 19, 2006, 10:37:52 AM »

That's an impressive accomplishment!  Most ancestor vs. current strain sims that I've done have the ancestor win out (That doesn't necessarily mean that the ancestor is more fit than the predecessor).

Yes, the ancestor strain usually does win and that was the idea. The setup I described really raises the bar for mutations to take hold. It created what I tend to think of as a sort of "genetic inertia" (yes I'm aware that I'm just making up descriptive terms!  ), so minor improvements and neutral mutations can't oust the ancestor strain in their "home" sim. It takes a genuine and significant improvement for the ancestor strain to be overrun in the low-mutation sim, and all the while if the high-mutation current strain falls below a certain threshold of fitness the low but regular introduction of ancestor strain bots wipes out the feeble descendants and starts the process again from a known competitive point.

I'd think that in some ways the net effect is similar to what you might get if you just vastly scale up the numbers in a single sim, just with lower computing costs.

It automates a lot of the saving and manually injecting test populations I used to have to do in several sims run consecutively. So you can see why I think everyone should be told, loudly and repeatedly, about the new teleporters function!

(Oh, and also perhaps a couple of hints about having to create a dir to use as a swapping area and having a separate dir for each teleporter pair might avoid 15 mins of head scratching like I had.)

51

Evolution and Internet Sharing Sims / Mutation Sims

« on: October 17, 2006, 06:43:26 AM »

The comment above about using teleporters to take advantage of multiple processors is pure gold. I did not know I could do that, and it has opened up some great possibilities for me.

The way I've got my setup running at the moment is to run two sims, a standard size one with bots and veggies and high frequency oscillating mutation rates (1 cycle at 16x, 3 cycles at 1/16x, no point mutations) and a large low-mutation one (1 at 16x, 19 at 1/16x, no point mutations) populated only with a fairly high number of veggies. Both have wandering teleporters set up to exchange only bots between the two.

The idea is that the bots evolve in the high-mutation sim and the teleporters occasionally transfer bots to the low-mutation sim. This sets up a stable population in the low-mutation sim, and regularly introduces bots from the high-mutation sim and transfers bots back to the high-mutation sim. If the currently-dominant strain in the high-mutation sim is not competitive against the low-mutation sim strain (in other words if the descendants are not competitive against their own ancestors) then the influx of ancestor-strain bots from the low-mutation sim will take over. If they are not significantly more competitive than their ancestors they won't get a foothold in the low-mutation sim.

The test sims I ran last night (about 7 hours worth) managed to avoid crunched descendants and showed definite evidence of improving fitness (introducing equal numbers of current-strain bots and ancestor-strain bots to a new sim meant that the current-strain bots always wiped out the ancestor-strain bots).

52

Evolution and Internet Sharing Sims / Mutation Sims

« on: October 16, 2006, 05:59:37 AM »

Interesting theory, I've always seen Point mutations as harmful, but I'd never considered them as the original driving force in starting the whole thing off. It certainly sounds plausible! I guess Point mutations would become even more harmful once you start getting multibots/multicellular organisms, nobody wants their left kidney to suddenly start moving around on its own or start to produce venom

On a similar note, I've been trying to "vaccinate" a bunch of not-top-rate bots like C. Ancestralis against some of the best by creating a weaker strain of predators (remove .repro and add randomised conditions to a few of the more important genes) and defining them as veggies with a very low pop cap and very very low rate of energy input. It requires a lot of supervision (killing off the predators if they get a little too successful, adding in the occasional batch of non-veg zerobots with high initial energy when the sim is getting a bit low on energy and occasionally repopulating the predators), and although I haven't had any dramatic successes they're starting to move in the right direction.

On your recommendation Testlund I shall prepare a zerobot evo sim. Does anyone have any recommendations for a good setup for this? I'd hate to evolve something useful only to have the entire thing go extinct on me minutes later!

53

Evolution and Internet Sharing Sims / Mutation Sims

« on: October 13, 2006, 09:50:35 AM »

I've been trying to run decent evo sims for a while now, my major breakthrough came when I completely disabled Point mutations. This allows each mutation to be evaluated for the entire life of the bot, so a bot that is "improved" by a mutation is not going to get a negative Point mutation to kill it off before it has a chance to pass on the goodness.

I'd also recommend setting an oscillating Mutation Rate, with 1 cycle at 16x and then 5 (or so) at 1/16x. This way there is a one in six chance of a high-mutation reproduction and a five in six chance of a low-mutation reproduction. This allows the dna to do some mutating, but if a bot is successful then five sixths of its offspring will be relatively unmutated. I find this strikes a nice balance between getting serious mutations and letting natural selection reward the fit.

54

Suggestions / Repopulating/Refreshing non-Veggies

« on: September 12, 2006, 06:12:49 AM »

It seems to be a fairly common theme on this board that evolution sims end up with fit bots evolving away from fitness. I believe this to be at least partly because all the bots are mutating simultaneously - eventually mutations will tend to crunch genes so that the bots are not competitive against the original "pure" genome, but mutations will also ensure that there are no "pure" bots left to compete against, so the standard of competition is reduced.

One way I've found to at least temporarily stave off this tendency is to reintroduce small populations of "pure" unmutated bots from time to time using the Bot Add tool. This ensures that the evolved descendants are forced to be competitive against the original genome, leading to a (slow) general trend towards improvement - a bot which is less competitive than its ancestors will be at a disadvantage.

Unfortunately this can't work for sims I leave running while I am out at work!

Would it be possible to introduce a mechanism to do this automatically? Along the lines of having options to reintroduce a customisable quantity of original-genome bots at a customisable interval?

55

Suggestions / Sexual Reproduction Focus Group

« on: September 07, 2006, 07:59:32 AM »

Not at all, feel free to put in up to and including $0.86

My only counterpoint is this question: does it add a new ability?  If it's just a segmenting of nrg, it doesn't do anything nrg by itself couldn't do.  Body, for instance, is used as a way to increase power.  Venom adds a new ability to the bot (venom shots).  etc. etc.  What does sex nrg do other than exist?

If you can think of a good reason for it to exist, then I wouldn't see any reason for it not to.

I was trying to come up with something that fitted in with the other features of the darwinbots system. If sex nrg is tracked separately as a "substance" like body, venom, slime etc. it could be transferred, shared and stolen by any of the means which are normally used for those substances, and reproduction would be linked to movement of sex nrg instead of calling an arbitrary function.

This allows the actual form the reproduction takes to be designed into genes using existing commands leading to more flexibility.

I'd say that this method does add a new ability to a bot - a bot which stores sex nrg will be able to initiate sexual reproduction. A bot which doesn't would still be able to participate, with weaker offspring because it wouldn't contribute sex nrg to the offspring's nrg total.

56

Suggestions / Sexual Reproduction Focus Group

« on: August 31, 2006, 10:35:16 AM »

Hi, I've been using Darwinbots for a few months now but I haven't actually posted on this forum until now.

Sexual reproduction is something I've been wanting for a while now, simply because all the long-term evolution sims I've run have ended with extinction. As far as I can tell sexual reproduction is a way of diversifying the population - the offspring is not limited to a single parent's genome plus reproductive mutations. And as I've learned over the last few months of running sim after sim after sim, a diverse population is a healthy population; monocultures are fragile and in a closed environment, ultimately a dead end.

I apologise for coming in the middle of this discussion with some ideas, if they're not welcome (or just no good!) just say.

Instead of sexual reproduction allocating a portion of the bot's current nrg to the offspring, perhaps nrg could be allocated to a "sexual reproduction bank" in a similar way to body, slime, shell etc. In this way preparing for reproduction is an investment, requiring "healthy" reproduction-concerned genes as well as general fitness, and selection pressures will favour organisms which allocate an appropriate amount and punish those who do not allocate enough (fewer breeding opportunities), or too much (less nrg available for living). Other bots may be written with or evolve a way use the amount of nrg stored in the bot's sexual reproduction location to gauge its suitability for mating. When the bot is involved in sexual reproduction it converts the value stored in the sexual reproduction location to nrg and passes it to the offspring.

The way I envision the actual reproduction mechanism operating is if a bot passes this sexual reproduction energy to another then the other produces a new bot with blended dna. If the system is set up so that this sexual reproduction energy can be sent via shot and tie then we can allow bot writers and evolution to work out what is best for their particular bot. So a sexual reproduction shot would include an amount of this sexual reproduction energy and the bot's identifier, sexual reproduction via ties would pass sexual reproduction energy and the bot's identifier (or maybe the tie number? Perhaps that might work better from the system's viewpoint). Perhaps the active part (the actual firing of the shot or the tie function) might be best expressed as firing a percentage of the sexual reproduction fund rather than absolute figures. The system generates a new genome from the two bots (perhaps the earlier two-halves method from earlier in this thread) and the bot that recieves the sexual reproduction energy adds the sexual reproduction energy from the shot to its reserve of sexual reproduction energy, converts the total to nrg and gives it to the offspring.

Just my $0.02, and as I said, feel free to tell me to shut up