Bots and Simulations > Simulation Emporium

Ways to increase natural selection?

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Gantolandon:
It seems that having more than two species increases natural selection.

My first simulation had somewhat mean algae (veggies, which tried to eat everything approaching), modified animal minimalis (eating body instead of energy, and growing) and a parasite. Improvement of this third species was my goal.

First I made it to attach to an organism which was turned back. Well... it weren't very successful, but a random mutation made it effective at least against the algae. Swirling in one place seemed to be a better strategy somehow, as it allowed to use the host as a morgenstern. I kept the mutated version, as it was clearly better than the original one. It still couldn't do much against animal minimalis, until I added a calming venom. It allowed to spray any organism in front of the parasite, making it not to attack this species.

Then the thing gone interesting. One particular mutation I remember was making the parasite attach not only to one organism, but virtually to anything, including their own siblings. They still sucked energy from the last organism they were attached to. A poor alga or animal minimalis couldn't do anything, as they were tied by multiple parasites. This net (or rather glue) made them unable to do almost anything. Veggies still could harness energy from the sun, but tied predators were doomed.

Then animal minimalis changed. They evolved into cannibots. Holding glue became a nice source of food for a short time, and they still could eat plants. Their reproduction slowed somewhat, but it were not a problem, as I somewhat castrated them earlier (in other simulations they were annoying me with rapid growth, so I culled their reproduction to 50 specimens). Parasites were in peril again.

Unfortunately, it was not a stable ecosystem. When I were in the kitchen, the plants somewhat eliminated everything. I still don't know how they did it...  

Peter:
Welcome to the forum.

Making stable sime with more then 2 species is kind of hard. Mostly after a time, one of the two species will extinct.
I gues this is becouse of that the enviroment in most sims is pretty simple and there is only one food source. Good you managed to do so.
The only reason algea could kil the others could be that they became carcerous. If you're using a sim where every algea gets a certain amount of nrg instead of kilobody, they could get as a group more energie this way and it means that it will get harder for preditors to get more nrg.

Gantolandon:
Thanks for the welcome

Nope. I used the sun model. I have seen cancerous algae only once. It's animal minimalis which become cancerous very often (which make me furious).

I certainly would like to know how to do a stable simulation... Even with two species the plants usually live only because of forced respawn...

EricL:
Welcome Ganto...

I tend to be a broken record on this subject, but part of the problem is our notion of "species".  Hand-authored bots of the same "species" only respect one another (presenting the illusion of a species) because they are coded to do so, but in reality, they are not a species in the sense that we use that term for sexually reproducing organisms, even on the first cycle when they all have the same exact genome.    Recognition of likeness for the purposes of reproduction is meaningless in asexually reproducing populations.   There is no gene flow between them except for direct line of descent.  It's little wonder that hand-coded bots in an evo sim go cannibalistic in short order.  Selection favors this since it conveys such a huge advantage to the first bot to violate the fragile and artificial (from selections point of view) conspec code.  

In evo sims, after a while, what appears to be a single species is in fact several (or better yet, hundreds) as the hand-coded conspec code breaks down and new systems evolve.  In an asexually reproducing population, the whole notion of species is suspect and may not even be relevant.  Sure, it helps to be able to recognize your offspring and not eat them, but families do not tend to group or otherwise remain in proximity and there are much easier ways for selection to avoid eating your young than conspec code.   One common way is simply not to eat (or not to be very effective at eating) heterotrophs at all.   There is no need for conspec recognition at all in a population of asexually reproducing herbivores.  All that is necessary is autotroph recognition and even then, it need not be explicit.  It could be as simple as just being a really really bad feeder when it comes to feeding upon others of similar genomes.  You may try to shoot or tie feed off your offspring or parents, but because you are so ineffective at it (they have slime or shell or similar) at least when you try it against others of similar genomes, the only things you end up really feeding off of are dumb plants.

Our genomes are too simplistic, our sims too small, our environments too simple.  There is little need for coordination between individuals and thus little reason for a bot to recognize others it might be related to as long as there is some mechanism at work, no matter how crude (like being a bad feeder) that serves to favor others of similar genomes.  

So, in most evo sims, I suspect there is more diversity then one might expect.  I have seen larger sims maintain independent families or "lines of descent" (a better term IMHO than "species" in asexually reproducing populations) for 100's of thousands of cycles.

You might try forking the species (use the Make New Species option) occasionally starting with the "Best Bot" and see how long the different families co-exist.  Family lines will eventually die out at some point as they get competed, even if families do not directly prey on one another, but you might find this takes much longer than you think.  These different families, while they co-exist, can be thought of as different species if you like since there is no gene flow between lines of descent (absent viruses).  

FYI, I will likely automate species forking in a coming version.

Peter:
I gues that if you hava a big enough sim you can keep multiple species for a long time. I zerobot-sims I had it have happening multiple times that there came multiple zerobots at some idea of 'reproducing'. It is somewhat annoying that they almost always just randomly write in their memory till they hit .repro.

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