Welcome
Watch multicellular life evolve through mutation, selection, crowding, predation, and changing energy conditions. The point is not to script behavior, but to build a world simple enough that useful strategies can discover themselves.
How It Works
Multi-cellular organisms act and reproduce in a 224x224 grid world (50,176 cells of space). Each organism is composed of different cell types with unique functions:
Teeth: Eating living tissue and decay
Nose: Smells nearby organisms
Eye: Detects cell types ahead and emitter signals
Emitter: Broadcasts a signal from 0 to 1
Energy Economy
- Photosynthesis: Photo cells gain energy only in lit areas.
- Shade: Nearby photo cells compete in local 3x3 neighborhoods, so crowded photo patches are less efficient.
- Metabolism: Most body cells cost 0.05 energy per tick. Eyes and noses currently have zero baseline metabolism.
- Movement: Successful movement costs 0.31 energy per cargo cell. Muscles, eyes, noses, and emitters are treated as free to carry.
- Brain cost: Brains pay 0.0002 energy per node per tick, plus 0.005 per hidden layer.
- Teeth: Adjacent bites recover structural energy and some stored energy, but repeated living-organism kills are limited by a digestion cooldown.
- Reproduction: Creating offspring costs 3 energy per cell and can happen either from brain output or automatically at high energy.
Sunlight Modes
Sunlight changes the geography of photosynthesis. Static plant-like bodies thrive in different places depending on how much of the world is brightly lit and how often those lit zones shift.
- Default: Sunlight is available everywhere.
- Central sunlight: Light is strongest in the center and gently falls off toward the edges instead of cutting off sharply.
- Refugia mode: The world alternates every 1000 ticks between uniform light and a concentrated refugia phase with five bright patches, each covering about 10% of the map.
Features
- Neural networks: Each organism carries a small feed-forward brain. Inputs depend on its body, but always include energy; outputs can drive reproduction, emitter intensity, and movement.
- Nose mechanics: Each nose scans a local 5x5 neighborhood and reports four directional density readings relative to facing: ahead, right, back, and left.
- Eye mechanics: Each eye reads the single cell directly ahead, with one input per cell type plus one input for emitter signal strength.
- Emitter mechanics: Emitters broadcast a 0-1 signal that eyes can detect, so they can evolve into simple signaling channels as well as environmental cues.
- Predation mechanics: Teeth bite automatically on contact, and movers get initiative after successful movement or rotation.
What To Watch For
- Punctuated dynamics: relatively stable intervals interrupted by extinction pulses
- Adaptive radiations and ecological reorganization following extinction events
- Refugia potentially supporting higher biodiversity and longer coexistence
- Oscillatory predator-prey dynamics, including overshoot, collapse, and transient shifts in trophic dominance
- Coevolutionary arms races between predators, prey, and defensive forms
- Attractor-like regimes in evolutionary space, with convergent evolution toward similar body plans in independent lineages
- Historical contingency and path dependence, with different runs settling into different long-lived regimes
- Possible evolution of sensory systems, especially noses and eyes, within mobile lineages
- Possible evolution of signaling through emitters and signal-responsive eyes
- Trade-offs between local specialists and generalists in variable sunlight regimes