Digital organisms run Turing-complete VM programs (46 opcodes) on a shared 2D grid. No fitness function. No selection pressure. No objective. Evolution emerges bottom-up.
python3 syntropy.pyCtrl+C to stop. Extinction summary on exit.
| Flag | Default | Description |
|---|---|---|
--seed N |
time | Random seed |
--width N |
72 | Grid width |
--height N |
26 | Grid height |
--tick-rate N |
0.06 | Seconds per tick |
--volume N |
0.3 | Sound volume 0–1 |
--no-sound |
— | Disable audio |
--max-energy N |
200 | System-wide energy cap |
--max-movement-speed N |
0 | Max moves/tick/org (0=unlimited) |
--continuous |
— | Auto-restart on extinction |
--log FILE |
extinction.json | Extinction log path |
Programs are lists of bytes grouped in 3-byte instructions: [opcode, a1, a2].
Execution is async per organism per tick. Energy = gas (budget up to min(energy×0.4, 8.0)).
| Cat | Opcodes |
|---|---|
| Flow | NOP, JMP, JZ, JG, JL, JNE, CALL, RET, HALT |
| Math | MOV, ADD, SUB, MUL, DIV, MIN, MAX, ABS, NEG, MOD, SQRT, EXP |
| Stack | PUSH, POP, DUP, DROP, SWAP, OVER, PICK, DEPTH |
| Bit | AND, OR, XOR, NOT, SHL, SHR, BIT |
| Compare | CMP |
| Random | RAND |
| Reg | IND, GEN, PC, SETPC, TICK |
| I/O | SENSE, ACT |
| Energy | ENERGY |
| Memory | MLOAD, MSTORE (16-slot persistent per-organism), GLOAD, GSTORE (64-slot shared world memory) |
Position, resources (food distance/direction), temperature, pressure, moisture, daylight, organisms (density, distance, direction), population, predator/prey/kin proximity, disease, season, terrain, traces, signals, symbol channel (symbol_id, symbol_val).
Move N/S/E/W, toward food, away from organisms, EAT, ATTACK, REPRODUCE, REST, SOUND, EMIT, SYMEMIT.
All organisms start at weight=1.0. Movement cost = 0.02 × speed × weight × dissipation
(speed = number of moves this tick, creating inertia). Each move burns 0.01 × speed weight.
Eating food adds weight; eating other organisms transfers their mass (requires heavier attacker).
Weight = 0 → wasting death.
Two genome banks per organism: genome_a (expressed) and genome_b (silent backup).
Active bank selected at birth. Gene conversion (2%/tick) copies a random byte from inactive to active,
providing automatic repair without explicit opcodes. Each bank mutates independently during reproduction.
Organisms deposit pheromones (trace=0.5/tick, decay ×0.95) detectable via TRACE sensor (radius 3).
EMIT action broadcasts a register value to nearby cells; SIGNAL sensor reads the buffer.
SYMEMIT broadcasts a typed (symbol_id, value) pair; SYMBOL_ID and SYMBOL_VAL sensors read the
dominant symbol at the organism's cell. Enables typed coordination and proto-language.
Enables communication, coordination, and memory sharing.
Per-organism persistent memory (16 float slots, opcodes MLOAD/MSTORE): survives across ticks for the lifetime of the organism. Allows learned state, counters, and context that persists.
World shared memory (64 float slots, opcodes GLOAD/GSTORE): a single global blackboard all organisms can read and write. Decays slowly (×0.998/tick). Organisms that evolve to coordinate through specific slots gain collective knowledge that outlives any individual.
Cultural transmission: on reproduction the parent's 16-slot memory is copied (with small Gaussian noise) into the child, creating a non-genetic inheritance channel that complements genome mutation. Learned behaviours can propagate across generations without being encoded in DNA.
3-band sound (bass/mid/treble) driven by SENSE→ACT SOUND. Environmental ambient audio
(pressure→bass, moisture→bass, temperature→mid, daylight→treble, season→sub-bass).
Async mixer with persistent aplay process and sample-accurate phase tracking.
- INITIAL_RESOURCES=60, RESOURCE_REGEN=3, REPRODUCTION_THRESHOLD=6.0
- Summer upkeep 0.06/tick, winter 0.12/tick
- System-wide energy cap (default 200): total organism energy+fat scaled proportionally when exceeded
- Energy dissipation above 5.0:
1.0 + max(0, energy-5.0) × 0.15— anti-hoarding pressure - Per-opcode instruction costs: NOP=0.002 to DIV/RAND/SENSE=0.016; SENSE/ACT add variable cost from a1
- Non-toroidal world (edges clamp) — edge ecology
- Day/night cycle with horizontal bar visualization
- Seasons (summer/winter) affect temperature and upkeep
- Temperature gradient: latitude + season ± diurnal cosine
- Disease, immunity, territory, nests, fossils
- Horizontal gene transfer, spontaneous mutation, fighting overlap
- Weak auto-eat (30%+age bonus) and auto-reproduce (10% at 2× threshold) for bootstrap
| Glyph | Meaning |
|---|---|
· |
Food resource |
⬟ |
Organism (varies by hue/energy) |
▲●★◆◉■⬢✦✧◈ |
Species glyphs |
✿ |
Corpse / special resource |
═══ |
Top/bottom bars with day/night coloring |
Status line: Pop, avg energy, avg weight, generation, avg age, species count, Shannon diversity, fossils, resources, season, tick, total system energy.
Python 3.10+. No external dependencies.