Author Topic: Natural Selection as an abstraction for game theory  (Read 6774 times)

Offline Numsgil

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Natural Selection as an abstraction for game theory
« Reply #15 on: December 05, 2006, 10:02:03 PM »
An addendum, at present the theory of natural selective abstraction is incomplete.  I don't have a a consistant way to determine if an abstraction ceiling exists.  That is, if there is an upper limit on the evolutionary stability of the number of levels of abstraction.  Or put another way, if complexity will increase.

My guess at the moment is that additional levels of abstraction require that "winning" the current abstraction layer adds some new rules to the game.  A successful replicator will now have to contend with the fact that other individuals will quickly exist that share any innovations it makes (close genetic relatives after a few generations).  This creates a race condition to develop innovations first, or otherwise be outcompeted (wether by being hunted or lacking physical space).  The thumb screws are tightened.

Any abstraction layer where winning does not create new rules will collapse back onto itself as mutations cause a splitting in the only surviving agent but nowhere to vent that splitting effect.  The current abstraction layer's game will simply eventually be played again with the mutated parts of the winning agent.  For instance, a planetary government would eventually collapse from in-fighting if constrained on our little Earth, because a world government seems to reduce the rule set instead of increasing it (wars are no longer an evolutionary pressure, and growth will eventually level off.)

In essence, my guess is that a new abstraction layer seems to form (that is, there is no abstraction ceiling) when you have these conditions:

1.  No other players in your current top level abstraction's game.

2.  Massive population increase / size growth.  Locality is reduced.

3.  There is Nash equilibrium type incentive for the sole surviving agent/player to fracture into new players / agents.  That is, cohesive forces are severely reduced.  Agents are rewarded for diversifying.

4.  Being the only player to survive the last game has somehow added a new rule to the game.  Most likely because you're game is larger in scope from the growth in #2 above.  Rules that were of little consequence before are now important.  For instance, a theoretical multicellular creature the size of Earth now has to deal with internal gravitational forces from its own mass.

Another example is oxygen producing algae having to deal with their own toxic output.  In some way, winning has changed the game.

------------------------
Using these 4 criteria I think it should be possible to examine any ALife simulator that suffers from little runaway complexity (like just about every simulator ever run) and determine a course of action to correct this.

In Darwinbots, the bottleneck is #3 and a little #4 I think.  There's certainly population explosions and competition driven extinction.
« Last Edit: December 05, 2006, 10:07:12 PM by Numsgil »

Offline Testlund

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Natural Selection as an abstraction for game theory
« Reply #16 on: December 06, 2006, 08:36:47 AM »
Quote from: Numsgil
I don't think all altruism in nature is tit for tat.  Certainly some of it is, but not all organisms have the capacity to remember the past actions of the other members in its group.

This is a good article about this very topic! Article.

That's an interesting article, though I don't agree with what it says about the monkeys and alarm calls. In nature ALL predators relies on the element of surprise at some degree. If a jaguar will be able to catch a monkey in the Amazon jungle the monkey has to be unaware about it's approach. If a monkey discovers it and start to give alarm calls it means it will be on guard and have much easier to escape from the jaguar. The jaguar instinctevly knows that and give up. It's probably not even worth it to try and find a silent monkey in all that noice.  
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Offline Numsgil

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Natural Selection as an abstraction for game theory
« Reply #17 on: December 06, 2006, 09:20:18 AM »
I think the idea is that the time spent being wary of predators has some fitness cost.  If you rely totally on others to tell you if there's a predator, you can spend more time digging for grubs.

Of course, if others learn this too and no one spends time watching for predators, everyone dies.

Offline Numsgil

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Natural Selection as an abstraction for game theory
« Reply #18 on: December 08, 2006, 04:19:10 AM »
I'm totally reformatting the "theory" above into very plain language in an attempt to make it more accessible to people who haven't had the mathematical and bilogical background I have.  As follows is a presentation of it that should be written in very plain terms without jargon.  You should be able to use this post and understand the comments I've made prior in the thread if you haven't been able to yet.

Natural selection is fundamental.  Basically, it says that organisms that are less capable of passing their essence to the next generation will be replaced by ones that are.  Natural selection is well observed and supported.  But it has a very area where it is useful.  Natural selection is difficult to apply in its direct form to understanding the nature of politics, economies, ecological forces, and other "macro", or large scale, phenomena, even though undoubtedly it is at the heart of these systems.

An interesting idea in the mechanics of natural selection came with Dawkin's selfish gene "framework".  I use the term framework instead of theory for a very important reason.  My first premise is that saying natural selection works on individuals trying to pass their genes to the next generation, and saying that genes are acting to propogate themselves are equivelant statements.  They're simply different ways of viewing the same phenomenon, and can be used interchangably depending on which one makes the most sense for the given question at hand.

An interesting consequence of this is kin selection, that is, performing benevolent acts towards another member of your family.  Since the other member of your family shares some of your genes, helping them survive and propogate also helps you spread your genes indirectly.

All organisms alive today are thought to have descended from a single ancestor.  If you were to follow this first ancestor, its kids, their kids, on and on until the present day, you could construct a phylogenic tree, also called a family tree.  All organisms alive today are related at least in some degree.

Game theory is a mathematical model that allows theorists to examine situations in which multiple agents, which can also be understood as "players" in a "game", interact strategically to maximize their wins, or alternatively, to minimize their losses.  I will be using the terms "game", which means a set of rules with consequences, and "agents", meaning players of a "game".  In this simple context, biological competition can be seen as a game, as can wars, economies, and just about everything that's ever been made into any sort of video game

What I propose is a framework for understanding the circumstances for certain observed facts in both real biology and Darwinbots evolutionary simulations.  The basic framework is something like this: agents in a game that do not manage to survive are ill represented in any slice of time.  Or put more simply, things that don't survive don't exist.  This is a generalization of the central tenant of natural selection to all processes, and forms the central tenant to my framework which I'll call abstract natural selection.  The premise is almost a tautology; it should be easily accepted.  The world around us is made of things that are good at existing. Things that aren't good at existing aren't very numerous.  Unstable crystals don't persist, unstable isotopes radioactively decay into stabler ones.

This should bring up a fundamental question in your mind.  How exactly am I defining "good at existing"?  A radioactive isotope with a half life of 100 years might seem stable from a human perspective but unstable from a geological time frame.  Is the isotope stable or not?  This is the second premise of the framework for abstract natural selection: the ability for an agent to survive in a game depends on the time frame your considering.  Or put another way, the ability for something to exist is a relative, qualitative term, and depends on the context in which you're using it.

Reality is made up of a hierarchy of different time frames you can observe the universe from.  If you view the universe in cosmological time, on the scale of the death and birth of stars, nothing is really all that permanent.  Stars are constantly birthing and dying.  Even black holes slowly evaporate into nothing through electron tunneling.  The next step up is geologic time, involving the development of crystals and minerals in the crust of the Earth.  In this time frame, the universe seems stabler, with stars lasting long enough for planets to form and their crusts to harden, etc.  Above geologic time is simple life, like bacteria.  Above that is the more complex life forms and their evolution.  Above that is ecology and the succession of grasses to trees in an area, and on up until you get to many human constructs such as economies and nations that have a cycle lifespan measured in centuries or decades or even just a few years.

Each time frame has specific rules unique to that time frame.  The goal for agents that play in these time frames is to exist.  Those that do are represented and exist.  Those that don't aren't.  Again, it's almost a tautology.  The universe is populated predominantly by very old, slow burning stars because the fast burning ones don't exist as long, and die out unrepresented, not existing.  The different rules come from the fact that the a force on one time scale might be insignificant, but on another time frame could be very important.  For instance, plate techtonics isn't all that important for the political life of nations, but it's had profound impacts on long term evolutionary development.

All these timeframes might have different rules, but they're also interacting.  If a star dies, any life on a planet around it dies.  There is constant feedback between the timeframes' games.  The universe can be seen as a large hierarchy of games being played in different time frames with different rules.  The outcome of games on one level of the heirarchy can effect the outcome of games on another

Now, back to our idea of a phylogenic tree.  Imagine grouping all the individuals that are related by being either parents or children of each other.  Groups will overlap, but you'll be able to do it.  Imagine treating these groups as new entities in a new phylogenic tree.  Imagine doing it over and over, creating larger and larger groups.  Eventually you'll have all life ever developed on Earth in a single group.  Now imagine the time frame that each group represents.  Singe generations are considerably shorter lived than, say, the entire group of 300 generations to which it belongs.  Each of these time frame's groups can be seen as agents in that time frame's game.  This means that agents that might be in direct competition in one time frame's game might be the same agent in another.  This is the fundamental lever point for my idea.  Depending on how you group life forms, you can change the rules by which those life forms are interacting, and even wether they're competing or cooperating.  Life can cooperate on one level and compete on another at the same time.

Note that not all agents in a time frame's game are necessarily competing.  Not all games are "zero-sum", where the winners winning comes at the expense of a loser.  In general if agents are competing, I'll say they are competing for a specific niche, where niche is another generalized term and simply means a limited resource.

Last, notice that games that occurr on shorter time frames have a faster pace.  Again, this is almost a tautology.  For instance, if a bacteria is killed by another bacteria, it's not really going to matter if it happens to live on a planet around a sun that's going to die in 3 billion or 8 trillion years.  Dead is dead, non existance is non existance.  Games that are played in shorter time frames have more weight than games that are played in longer time frames, because their paces are faster and their effects more immediate.

-----------------------------------------------------------------

That defines the base of my idea in its entirety.  Some of the basic premises might be unfounded, but alot of it is simply reorganizing existing facts to allow us to look at data in a new way.  It is particularly useful for explaining some rather peculiar things I've seen that would seem to contradict Dawkins claim that selection at the level of organisms or populations almost never overrides selection on genes.  For instance:

Cannibalism and the leagues - There is something of a pardox to the following fact: conspec recognition in leagues is important for success.  Bots that eat their children or other members of the species will not do as well against another species that doesn't.  However, in evolutionary simulations, this conspec recognition always, except in extremely contrived situations, is selected against and disappears.  What's odd is that it usually follows a reverse pattern to kin selection: when it first appears, it's almost always indiscriminate eating of everything, and is usually first directed at fellow siblings and even the parent, and only later is the bot able to find less related bots to much on.  These bots also seem less able to bear young successfully, with the number of successful reproductions much lower than the unmutated forefather.

Using the Framework of Abstract Natural Selection (FANS) allows us to state and understand the phenomenon on very real terms.  When a bot species is fighting another bot species, the entire battle usually is measured in the low thousands of cycles.  "Cannibots" usually appear after some time of mutations has occurred, somewhere on the order of hundreds to low millions of cycles.

Battling against other species occurs in a slightly different time frame.  In this time frame, the two species are battling for a single niche (victor of the round).  All bots of a single species are essentially the same agent, and it would not be wise for an agent in a zero sum game to fight against itself, which is why cannibalism doesn't work in the leagues.

In the longer term, however, the fight for the niche will long be over, and only a single bot species will survive.  In this long term there is no more game to play in the shorter term, since it's already been played and won.  The most significant game is now the battle between individuals to survive (not even to necessarily pass on their genes.  That's a longer term, multigenerational game).  At first, since they have a conspec recognition gene and all bots are essentially identical, the only way to survive better and have more kids than someone else is to be lucky enough to either stumble onto a fresh veggy patch or have a veggy spawn right next to you.  If you are always crowded out of these new veggies, you will die.  Dumb luck really.  And since no one is being actively hunted by anything, life span can be very long.

However, eventually a cannibot will develop.  This cannibot has a huge advantage in the game of surviving because it actively destroys other agents.  It no longer needs to get lucky and find a new veggy patch or have one spawn, because it's eliminating any other potential rivals for food.  And it's easy pickings because they don't fight back.  What I'm saying is that cannibots develop not because it's a new food source (although that's an important plus), but because it's a trait for eliminating rivals.

In essence, cannibots don't work in the leagues because in that time frame, the species are the agents and cannibalism would be like suicide.  Cannibalism works after a league is done, in longer term evosims where all the bots are basically very similar, because the time frame and thus the rules of the dominant game and the definition of an agent, change.

To test if this idea is true or not, we'd have to figure out some way to rig up a league round with mutations enabled that would last longer than it usually takes for cannibots to develop and dominate the sim, but isn't setup in such a way that the bots co-exist.  One needs to eventually win.  If the cannibots still develop, spread, and belong to the species that wins the round, this would disprove this explanation.  If they don't, that would be strong circumstancial evidence.

Big berthas - Big berthas are very large, very sterile bots that constantly shoot.  They used to develop in evo sims before I increased the problems associated with waste.  Basically, a bot would break its gene to reproduce, and would instead constantly acquire nrg and body.  The body would make it stronger and basically unkillable by the smaller, reproducing bots.  5 or 6 Big berthas would eventually kill all strains of reproducing bots, causing a mass extinction event when the big berthas eventually died.  What's interesting is that these 5 or 6 big berthas would all be independant mutations since the big berthas never reproduced.

Reconciling this with natural selection presented me with some problems.  These bots would appear "fitter" since eventually they'd replace all the reproducing bots.  But there was no hope their genes being passed on to the next generation or even surviving indefinately, since eventually costs would kill the big bertha and its genes with it.  It was the very definition of dead end.

However, if you use FANS this makes sense.  Big berthas were unkillable.  Usually a single hit from one of its shots would kill another bot.  Similar to cannibots, their survival in the contest against other individuals was all but insured.  In their young life they had to contend with other bots' crowding them out for food, accidentally killing them with stray shots, and even being hunted by smaller cannibots.

However, once they were monstrous, other bots simply couldn't kill it.  They had effectively won the more dominant game of surviving against other individuals.  Unfortunately, the selective pressures for this game also caused them to adopt a strategy that wasn't beneficial in the less dominant game of long term survival of the genome.  But these longer term selective pressures didn't get to act until the big berthas had decimated all other kinds of bots, and by then it was too late.  Again, shorter term games have stronger pressures.  Bots will sacrifice success in the longer term games for success in the more immediate moment, mostly because evolution isn't forward thinking, and doesn't know better.

These two examples show how FANS can be used to understand why you see evolution proceed along paths that in the long term are less effective.  It can be used to explain why you see bots "devolve" in long term simulations.  To understand the other half of my idea, about the "abstraction ceiling" try reading the other posts again after reading this.
« Last Edit: December 08, 2006, 04:35:51 AM by Numsgil »

Offline Jez

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Natural Selection as an abstraction for game theory
« Reply #19 on: December 08, 2006, 09:58:43 AM »
Sorry about the previous spelling and grammar errors in my previous posts, it led to some misunderstandings and I blame it all on my keyboard.

I've done a little bit of reading on games theory/Nash/Evolutionary stable strategy/Evolutionary games strategy/Muller's ratchet etc, in the hope of understanding what I'm talking about a little better.

I'm not going to attempt to reply to everything you have raised all at once either. I'm pretty much just going to make some cursory replies to your last post.

First though, the definition of Altruism particuarly in ethology and evolutionary biology : Altruism

"Altruism refers to behavior by an individual that increases the fitness of another individual while decreasing the fitness of the actor."
"Recent developments in game theory have provided some explanations for apparent altruism, as have traditional evolutionary analyses."
Also a more expansive explanation of the slime mould altruism;
"An interesting example of altruism is found in the cellular slime moulds, such as Dictyostelium mucoroides. These protists live as individual amoebae until starved, at which point they aggregate and form a multicellular fruiting body in which some cells sacrifice themselves to promote the survival of other cells in the fruiting body"
"In the context of biology, the "Tit for tat" strategy is also called reciprocal altruism or Mutual Aid"

Plus the maths bit;
"If a gene copy confers a benefit B on another vehicle at cost C to its own vehicle, its costly action is strategically beneficial if pB > C, where p is the probability that a copy of the gene is present in the vehicle that benefits. Actions with substantial costs therefore require significant values of p. Two kinds of factors ensure high values of p: relatedness (kinship) and recognition (green beards). (Haig, 1997, p. 288)"

Cannabilism and the leagues
That non DB evolutionary sims usually select against cannabilism isn't that surprising, I do think that a cannibot in DB does tend to pick on it's children and kin first simply because they are closer and easier to get at. As it tends to eat its babies it also shows a lower succesful repro rate. In that sense and considering some of the first league bots, which were cannibals, I think that it is the size of (homo species) sims that causes them to be a relatively succesful evolution.
I think cannibots evolve as a way of exploiting a new food source, there isn't anything to stop it becoming omnivorous. Bots like doing the smallest amount of work for the largest reward. Rivals would have to include copies of its own code for that to be the reason it formed, that seems self defeating genetic evolution. It is not a good way for genes to increase the numbers of copies of their genetic code.

To test out evolution over a multi species competition you would need to start with a large sim, plenty of veg and bots that aren't very good at getting enough food to eat. They couldn't be cooperative bots nor a bot that was capable of a sim dominating max pop. Good luck, I've tried doing similar things in the past.

Big Berthas
Had a thought, perhaps this is because there is no disadvantage to being big, no reason to shed excess energy or body. If we started adding disadvantages, and I'm sure there must be biological comparisons, for getting over a certain amount of energy of body mass. More so than the energy required to move that we have atm. Perhaps the problem would be more self defeating, bots would need to reproduce to lose the excess baggage.
Again though, because of the slowness of the Berthas, their stationary existance, perhaps the size of the sim has a part to play in their formation. A few Berthas can succesfully dominate a sim before death rebalances the problems caused by their sterility.

I'm probably being pedantic again I know, I like the idea of having a more structured framework with which we can analyse bot evolution though.  

I guess I'll go and read a bit about FANS now, so much for speedy answers.  
« Last Edit: December 08, 2006, 10:05:29 AM by Jez »
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Offline EricL

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Natural Selection as an abstraction for game theory
« Reply #20 on: December 08, 2006, 12:20:23 PM »
Quote from: Numsgil
An interesting idea in the mechanics of natural selection came with Dawkin's selfish gene "framework".  I use the term framework instead of theory for a very important reason.  My first premise is that saying natural selection works on individuals trying to pass their genes to the next generation, and saying that genes are acting to propogate themselves are equivelant statements.  They're simply different ways of viewing the same phenomenon, and can be used interchangably depending on which one makes the most sense for the given question at hand.
I disagree that they are equivalent statements.  Where the decision/motivation to perform an altrusitic act resides is the crux.  With genes as the principle actors, altruistic behaviour by the organism such as kin selection is explained by pre-programmed tendencies in the organism (including meachanisms that go with it such as the ability to guage relatedness) I.e. people perform altrusitic acts in cetain cases because their genes have found it a succesful strategy to do so.  Saying the individuals are the actors implies a choice made by the organism independent of the genetic programming.

Quote from: Numsgil
Even black holes slowly evaporate into nothing through electron tunneling.
I beleive Hawking's theory has been disproved for all but quantum black holes.  Black holes above a certain mass threshold will never evaporate.

Quote from: Numsgil
Cannibalism and the leagues - There is something of a pardox to the following fact: conspec recognition in leagues is important for success.  Bots that eat their children or other members of the species will not do as well against another species that doesn't.  However, in evolutionary simulations, this conspec recognition always, except in extremely contrived situations, is selected against and disappears.
As I have said before, there is little reason for asexually reproducing organisms not to be cannabilistic.  There is no gene flow between members of an asexually reproducing 'species' through sex and recombination, only through descent.  Thus, there is no gene-based evolutionary advantage to evolving species recognition or relatedness mechanisms (much harder than it sounds) and practicing kin altuism.  But what we are really seeing in DB evo sims IMHO is even simiplier than that.  In every evo sim I've seen where selection is operating (not the first days of a zerobot sim) bots in proximity are all descended from a recent common ancestor.  Thus, ALL bots in the sim are a close relatives through descent.  There is no way be a carnivore and NOT to be cannabilistic.  We don't have the diversity of niches (yet) to support speciation in proximity.  We really can't even talk about multi-species issues yet becuase we have yet to evolve multiple species.

Quote from: Numsgil
When a bot species is fighting another bot species, the entire battle usually is measured in the low thousands of cycles.  "Cannibots" usually appear after some time of mutations has occurred, somewhere on the order of hundreds to low millions of cycles.

This is not an evolutionary phenomem.  This IMHO is simply a degrading of hand-coded programming when a human authored machine is subjected to mutations.  Multiple hand-coded organisms in a sim is not a natural or evolved state and it is incorrect to call them different species.  Humans wrote the code to avoid attacking other bots based upon some artifical identification mechanism.  Humans invented this notion of species.  It has nothing to do with evolved darwinian speciation or kin selection.  None of the code, behaviour or identification is evolved.   What we think of as species in DB is a flawed concept or at least not a darwiniam concept and species related conclusions based upon it is IMHO flawed.

Quote from: Numsgil
Battling against other species occurs in a slightly different time frame.  In this time frame, the two species are battling for a single niche (victor of the round).  All bots of a single species are essentially the same agent, and it would not be wise for an agent in a zero sum game to fight against itself, which is why cannibalism doesn't work in the leagues.

Cannibalism doesn't work in leauges because humans programming their agent machines to destroy one another is simply not a winning strategy.  It has nothing to do with evolution, species or evolved cannabalism.

Quote from: Numsgil
However, eventually a cannibot will develop.  This cannibot has a huge advantage in the game of surviving because it actively destroys other agents.  It no longer needs to get lucky and find a new veggy patch or have one spawn, because it's eliminating any other potential rivals for food.  And it's easy pickings because they don't fight back.  What I'm saying is that cannibots develop not because it's a new food source (although that's an important plus), but because it's a trait for eliminating rivals.
I would claim this is just the human authored machine deteriating further, falling down off a naturally unobtainable peak in the fitness landscape and that making conclusions based upon simulations which start with anything more complex than the simplest replicator (and certainly conclusions which rely upon some human defned concept of species) are flawed.  As above, IMHO the whole notion of what we call species in DB is artifical, arbitray and very unrelated to actual speciation in DB, if and when we see it evolve (to my knowledge, we have not seen it evolve when bots are in proximity).  We should not act surprised when a human coded gene breaks down and starts doing something different than it's author intended.  Your overall theory may be correct, but IMHO, using examples based upon human authored bots and artifical, human defintions of species and drawing big conclusions about cannabalism or something from that is not supportted.

Quote from: Numsgil
Big berthas - Big berthas are very large, very sterile bots that constantly shoot.  They used to develop in evo sims before I increased the problems associated with waste.  Basically, a bot would break its gene to reproduce, and would instead constantly acquire nrg and body.  The body would make it stronger and basically unkillable by the smaller, reproducing bots.  5 or 6 Big berthas would eventually kill all strains of reproducing bots, causing a mass extinction event when the big berthas eventually died.  What's interesting is that these 5 or 6 big berthas would all be independant mutations since the big berthas never reproduced.

Big Berthas are in my opinion, simply an aberation that occurs in sims that do not have the costs/environment/diversity to select against them.  In a rich enough, large enough, diverse enough sim, some bot would eventually evolve to take advantage of the nrg source they represent.  

You theories as related to gaming, etc. may be sound, but I think you are on shaky ground drawing conclusions from DB which are based upon hand-coded bots and human-defined notions of species.
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Offline Numsgil

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Natural Selection as an abstraction for game theory
« Reply #21 on: December 08, 2006, 03:18:55 PM »
Quote from: EricL
I disagree that they are equivalent statements.  Where the decision/motivation to perform an altrusitic act resides is the crux.  With genes as the principle actors, altruistic behaviour by the organism such as kin selection is explained by pre-programmed tendencies in the organism (including meachanisms that go with it such as the ability to guage relatedness) I.e. people perform altrusitic acts in cetain cases because their genes have found it a succesful strategy to do so.  Saying the individuals are the actors implies a choice made by the organism independent of the genetic programming.

If you are examining things with individuals being the agents, then you need to use the concept of intrinsic fitness.  By redefining the concept of what an "individual" agent is for natural selection to operate on, you're changing the rules.  This is key: they are equivalent statements (isomorphic), but the mapping changes the basic rules of selection.  What I'm proposing is that you can do this all the way up, using intrinsic fitness at each level to make the concept of an "agent" more inclusive.  But doing this changes the rules of the game for the agents to play.  Determining these rules is outside the scope of my framework.  What it does say is that faster paced games have more weight for selection.

It's a sort of recursive subdivision.  Hopefully this makes sense to you?

Quote
I beleive Hawking's theory has been disproved for all but quantum black holes.  Black holes above a certain mass threshold will never evaporate.

Okay, I'm going to call you on this!  I haven't heard anything of the kind.  Where did you read this?  What was Hawkins reply?  Is it a new, still contested point that disproves the idea of black hole evaporatioin, or is it an overlooked flaw in Hawkins proof?

Quote
As I have said before, there is little reason for asexually reproducing organisms not to be cannabilistic.  There is no gene flow between members of an asexually reproducing 'species' through sex and recombination, only through descent.  Thus, there is no gene-based evolutionary advantage to evolving species recognition or relatedness mechanisms (much harder than it sounds) and practicing kin altuism.

I am aware of nothing that prevents asexual creatures from practicing kin selection.  Actually, since close relatives are more likely to be 100% genetically identical, kin selection would seem to be even stronger.  Why doesn't kin selection develop?  Under what conditions does it "devolve", and under what conditions does it persist?  I also find it extremely naive to simply say "there is no gene-based evolutionary advantage".  It's begging the question.  It's about as useful as saying "because God wants it to".  It's almost a truism, and it doesn't help us understand why.

Quote
This is not an evolutionary phenomem.  This IMHO is simply a degrading of hand-coded programming when a human authored machine is subjected to mutations... It has nothing to do with evolved darwinian speciation or kin selection. None of the code, behaviour or identification is evolved. What we think of as species in DB is a flawed concept or at least not a darwiniam concept and species related conclusions based upon it is IMHO flawed.

 Multiple hand-coded organisms in a sim is not a natural or evolved state and it is incorrect to call them different species.  Humans wrote the code to avoid attacking other bots based upon some artifical identification mechanism.  Humans invented this notion of species.

...

I would claim this is just the human authored machine deteriating further, falling down off a naturally unobtainable peak in the fitness landscape and that making conclusions based upon simulations which start with anything more complex than the simplest replicator (and certainly conclusions which rely upon some human defned concept of species) are flawed.

Here is where I will vehemetly (sp?) draw the line.  The hand coded bots are acted upon by mutations.  They must be subject to the law of natural selection same as every other mutating and reproducing entity in the whole of the universe.  Shot bots don't lose the ability to shoot.  That's a hand coded trait that's evolutionarily stable.  Reproduction and movement are iffier, and are related to the size of the simulation, and how much it is well mixed.  Conspec recognition is the first thing to go in an evo sim.  Clearly there is strong selecting pressure against it.

Remember, mutations act on the genotype, but natural selection acts on the phenotype.  Your argument assumes that because a genome is highly artificial, and prone to any mutations breaking it, that must mean that the phenotype is likewise easily broken.  If this were true, we'd see all the behaviors of bots (vision, movement, reproduction, shooting, and conspec recognition) fail at frequencies related to their genotypical complexity.  We don't.  Our bots are subject to natural selection.  Always.

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Cannibalism doesn't work in leauges because humans programming their agent machines to destroy one another is simply not a winning strategy.  It has nothing to do with evolution, species or evolved cannabalism.

That's my point!  It's not a winning strategy for a species.  Which can be seen as a single agent, because all the bots are somewhat genetically similar compared to another species.  It's immaterial how we define the species, because at the start of the league, all bots that share a "species" label are 100% identical, and 100% unidentical to the other species.  At the end of a round, the game is "won", there is only a single agent.  This causes this levels game to be given a weight of zero, and the next weighted game is the competition between individuals.

Strategies that are successful in one game can be harmful or unstable in another.  What matters is the weight of the respective games.  Faster paced games (league battles) are more strongly weighted.  Again, we can test this hypothesis by figuring out a way to extend most leagues battles into the millions of cycles (larger arena maybe, we'd have to test it) and allowing mutations into the round.  My hypothesis says that species who develop cannibots will lose, or actively fight the cannibot.  If it loses, it won't be represented in the future of the sim, because it will not exist.  We will see the longterm incidence of cannibalism be very low in winning species.

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IMHO, using examples based upon human authored bots and artifical, human defintions of species and drawing big conclusions about cannabalism or something from that is not supportted.

Using artificial bots is important because it allows us the specificity and variable limiting that is important in good science.

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Big Berthas are in my opinion, simply an aberation that occurs in sims that do not have the costs/environment/diversity to select against them.  In a rich enough, large enough, diverse enough sim, some bot would eventually evolve to take advantage of the nrg source they represent.

This is very poor science.  You cannot place all the data that you don't like in the neat little category of "outlier", especially if it's data that's very common.  And not just in Darwinbots, there are all sorts of circumstances where evolution has proceeded down a course that ultimately leads to the population's extinction.

My framework allows us to examine the reasons why.  And it's not all that novel.  All it's saying is that evolution is very short sighted, and will react to local pressures more strongly and more immediately than it will react to global pressures.  Evolution will lead to its own destruction at certain times.  It doesn't need a mutation meltdown, it doesn't need mueller's ratchet.

Really, this shouldn't be a hard pill to swallow.

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You theories as related to gaming, etc. may be sound, but I think you are on shaky ground drawing conclusions from DB which are based upon hand-coded bots and human-defined notions of species.

The idea works eaqually well with real observed phenomenon.  For instance Slime mold altruism.  Developing slime molds that break their altruism gene is very easy in the laboratory, even common.  My framework allows us to see selection in nature as a competition between rival slime mold colonies.  In this competition, cheaters cause their host slime mold colonies to be less successful, and they'll be eliminated by other successful colonies.  In a lab, this higher, faster paced selection is not available, and the next slowest game, competition between individuals, is the dominant game.

Note that my framework does not allow us to see how.  It's outside the domain of my framework to say how slime molds react to cheaters, or how cheaters influence the success of their colony beyond saying that if it will quickly cause their colony to no longer exist in the genotype of the future generations, it will not exist in future generations.

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Any real criticism of my framework should really be of the counter example variety.  Everything my framework is based on should be either self evident or at the very least a valid current scientific theory (though perhaps hotly debated.  I won't spend the time to defend intrinsic fitness).

Phrased another way, my framework basically says is that evolution is short sighted, and short term benefit overrides long term detriment.

Offline EricL

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Natural Selection as an abstraction for game theory
« Reply #22 on: December 08, 2006, 04:19:51 PM »
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Okay, I'm going to call you on this!  I haven't heard anything of the kind.  Where did you read this?  What was Hawkins reply?  Is it a new, still contested point that disproves the idea of black hole evaporatioin, or is it an overlooked flaw in Hawkins proof?

Will reply at length to main topic later.  On this aside, I must apologize.  I mispoke.  The theory has not been disproved.  Rather, the calculations show that the mass loss due to Hawking radiation from any black hole above a certain relativly small size will be exceeded by the mass intake due to cosmic background radiation.   If I remember correctly, this size is much much smaller than the minimum size possible for a black hole formed via stellar collapse and thus only theoritical, so-called quantum black holes will evaporate (and even these, if such exist, will take many times longer than the age of the universe to do so).  This is pretty old news and came to light shortly after Hawkings famous 1974 paper was published.
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Offline Numsgil

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Natural Selection as an abstraction for game theory
« Reply #23 on: December 08, 2006, 11:15:48 PM »
Interesting.

My understanding is that if the present acceleration of the expansion of space continues unabbated, eventually it would reach a point that even the strongest gravitational forces would be overcome by the sheer expansion of space, eventually destroying all matter, including blackholes.

Interesting stuff, even if it's sort of off topic

Offline Numsgil

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« Reply #24 on: December 09, 2006, 12:35:49 AM »
A short postscript.  If you take the entire phylogenic tree and bind it together as a single agent, you would basically have the same things as Gaia theory.  I think this fact is very helpful in illuminating where I'm comming from.  It's very much in the same boat as Gaia theory.

Offline Numsgil

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« Reply #25 on: December 11, 2006, 04:31:30 AM »
Wikipedia has done a better job than I have of explaining what I mean by "abstraction levels" and time frames.  Clearly I'm not the first person to examine natural selection in this way.

What I think is unique, however, is my saying that indirect fitness, that is, the fitness of relatives multiplied by their degree of relatedness, can be recursively applied to a group of increasingly non related organisms, and that each group identified in this way, can act as a unit of selection in a different context.

BTW Jez, Big Berthas did disappear in most simulations when I increased the effects of waste, particularly permanent waste.  As you say, once there was a drawback to never reproducing, we stopped seing big berthas totally dominating a simulation.

Offline Jez

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« Reply #26 on: December 11, 2006, 05:07:47 AM »
Cool! Thanks for testing it.

Actually I originally suggested waste as a form of disadvantage for cannibots, when it comes to Berthas, was more thinking of a disadvantage for a cell getting over a certain size (rather than punishing for non repro, sterility is an advantage for some species, ie ants and if humans are anything to go by sterility is possible for individuals without affecting species). A sort of altzheimers effect similar to the waste effect I guess if body gets over a certain value.

What you've done is sensible though, you have shown that Bertha's are a program anomaly not an evolutionary one. Funny how the bots are always ready and willing to exploit any part of the program landscape, niches if you like, that haven't been given disadvantages. Does make you wonder, if we ever get the proper balances in place, how exactly the bots would mimic biological evolution.

I'll have a go at reading that wiki entry sometime soon.
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Offline Numsgil

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« Reply #27 on: December 11, 2006, 05:17:58 AM »
I don't know that it's necessarily showing that it's a program anomaly only.  It's still an interesting phenomenon where individual selection causes the eventual extinction of all life.  It hasn't happened like that in real life because the real universe has been smart enough to give every advantage an associated disadvantage

Offline Jez

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« Reply #28 on: December 11, 2006, 05:37:19 AM »
Quote from: Numsgil
to give every advantage an associated disadvantage
That's the words I was looking for!

DB has pretty well balanced disadvantages for most of the bot abilities,or should have. bots that develop to the extreme of an ability show where the disadvantages aren't balanced correctly IMO. I've never actually thought of looking at DB that way...

It is interesting, DB needs to be cruel to be even a pale imitation of the universe. Without punishing the 'weak' there is no evolution.
« Last Edit: December 11, 2006, 05:38:00 AM by Jez »
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Offline Numsgil

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« Reply #29 on: December 17, 2006, 06:53:52 PM »
This is a good overview of altruism in the sort of environments DB represents.
« Last Edit: December 17, 2006, 06:54:48 PM by Numsgil »