Pixie and Super Pixie
Watching other artificial life programs it's easy to suspect Intelligent Design, that the emulated creatures' behaviours are so sophisticated that they must have been written into the code by a Creator. But when you write your own trivial code and complex life-like things emerge from it, it's just spooky.
On the left is a basic world with green plants, blue herbivores and red carnivores (see previous post for more introductory detail). It doesn't evolve dark green plants as in the carnivore-free example, presumably because the carnivores prevent any form of stability appearing, and chaos favours very efficient plants which can re-colonise devastated areas quickly. There are some short-term shadings in the green, but it gets erased as waves of blue and red pass over it.
The carnivores are hard to see at this scale because they're so few, as they would be in most food chains, since they're at the top and most of the energy input at the bottom is lost as it passes to them through the plants and herbivores. There is some clustering of each species, but no particularly interesting structure to it.
The magic only appears (picture on right) if the cost of living is reduced for each pixie, allowing much more energy to reach the carnivores, so they bloom. Now they form packs that follow blue herbivore herds advancing in jagged crescents through large areas of plants. (Easier to see in the running program, with movement indicating clear front and back to each grouping.)
The small scale chaotic structure is replaced by discrete larger ordered structures, and it's difficult not to see the red/blue shapes as themselves being the creatures in this world. Like multi-celled animals, the red core moves around the landscape fronted by a blue feeding membrane, which takes in green food and processes it into meat for the core.
Of course there are no such creatures in the code, they are entirely emergent effects of single pixel actions, just as multi-celled biological creatures appear to have individual behaviour, but actually consist of many cells each responding to their immediate neighbours.
Reducing the cost of living further increases the effect (picture on left), as if more energy for the carnivores allows them to organise the world better for their own most effective feeding and breeding.
Curiously, there are never any independent blue areas: every herbivore is part of a herd attached to a carnivore pack. It's not that the carnivores are herding them (in the Masai/Bahktiari pastoralist sense), since the carnivores are just following them (more like Lapps and reindeer). It looks more like endosymbiosis, where lifeforms of different species are always found together because they breed together, and of course there's no code for that either.
It's also remarkable that the world is stable, though the composite "animals" have a short life-span as individuals (when they collide their fronts are deprived of plant food and die off, which in turns starves the carnivorous core), but new ones keep appearing to maintain a constant population. It looks as though they are being constantly seeded by some external Creator, but they aren't. They are born from odd bits left behind by the passage and death of "parent" composites, and again there's no code to make that happen.
I thought it might be just luck at first, but it keeps working over many thousands of generations, so perhaps it's intrinsic to the system in some way. Life's full of mysteries.
Technical stuff: if you'd like to download the Pixie World program and play with it, you'll need a Windows machine (sorry) for the pixie binary, which has instructions under "Help" on the "Main Menu". This program expects to run with Cygwin (Unix on Windows - you didn't expect me to use a real Windows environment for my first programming on it?) but if you don't have that installed, it seems to be enough to just download this file into the same directory as the pixie program. Cygwin itself is entirely free downloads so this probably isn't naughty.
On the left is a basic world with green plants, blue herbivores and red carnivores (see previous post for more introductory detail). It doesn't evolve dark green plants as in the carnivore-free example, presumably because the carnivores prevent any form of stability appearing, and chaos favours very efficient plants which can re-colonise devastated areas quickly. There are some short-term shadings in the green, but it gets erased as waves of blue and red pass over it.
The carnivores are hard to see at this scale because they're so few, as they would be in most food chains, since they're at the top and most of the energy input at the bottom is lost as it passes to them through the plants and herbivores. There is some clustering of each species, but no particularly interesting structure to it.
The magic only appears (picture on right) if the cost of living is reduced for each pixie, allowing much more energy to reach the carnivores, so they bloom. Now they form packs that follow blue herbivore herds advancing in jagged crescents through large areas of plants. (Easier to see in the running program, with movement indicating clear front and back to each grouping.)
The small scale chaotic structure is replaced by discrete larger ordered structures, and it's difficult not to see the red/blue shapes as themselves being the creatures in this world. Like multi-celled animals, the red core moves around the landscape fronted by a blue feeding membrane, which takes in green food and processes it into meat for the core.
Of course there are no such creatures in the code, they are entirely emergent effects of single pixel actions, just as multi-celled biological creatures appear to have individual behaviour, but actually consist of many cells each responding to their immediate neighbours.
Reducing the cost of living further increases the effect (picture on left), as if more energy for the carnivores allows them to organise the world better for their own most effective feeding and breeding.
Curiously, there are never any independent blue areas: every herbivore is part of a herd attached to a carnivore pack. It's not that the carnivores are herding them (in the Masai/Bahktiari pastoralist sense), since the carnivores are just following them (more like Lapps and reindeer). It looks more like endosymbiosis, where lifeforms of different species are always found together because they breed together, and of course there's no code for that either.
It's also remarkable that the world is stable, though the composite "animals" have a short life-span as individuals (when they collide their fronts are deprived of plant food and die off, which in turns starves the carnivorous core), but new ones keep appearing to maintain a constant population. It looks as though they are being constantly seeded by some external Creator, but they aren't. They are born from odd bits left behind by the passage and death of "parent" composites, and again there's no code to make that happen.
I thought it might be just luck at first, but it keeps working over many thousands of generations, so perhaps it's intrinsic to the system in some way. Life's full of mysteries.
Technical stuff: if you'd like to download the Pixie World program and play with it, you'll need a Windows machine (sorry) for the pixie binary, which has instructions under "Help" on the "Main Menu". This program expects to run with Cygwin (Unix on Windows - you didn't expect me to use a real Windows environment for my first programming on it?) but if you don't have that installed, it seems to be enough to just download this file into the same directory as the pixie program. Cygwin itself is entirely free downloads so this probably isn't naughty.