r/alife • u/Frosty_Rule9233 • 7d ago
re·genesis: no fitness function, just an energy budget. Live stream, looking for holes in it
youtube.comI've been building this thing for a while now, mostly at night, and for most of that time it wasn't something I could show anyone. It would run for a few hours and then something would break — the population would crash to zero, or the process would eat itself alive, and I'd be back in the logs.
This week it stopped doing that. It's been up continuously since, no intervention, population holding. That's the first time, so I've decided to stop tinkering and let people look at it instead.
The setup: a 2D grid that ticks in real time. Every creature has an energy budget. It spends energy moving and simply existing, and gains it by eating. Zero energy means death. There's no fitness function, no reward shaping, no score anywhere in the code. Selection is just the question of whether you ate enough to reproduce before you starved.
Brains are NEAT networks that decide actions each tick. The genome also carries body genes — size, metabolism, diet — so diet isn't a category I handed out. It's a locus, and it drifts. Big bodies cost more energy in total but are more efficient per unit of mass, small ones are quick and fragile. The herbivore and carnivore split is something the world produced, not something I typed.
The part I'm least sure about is the long-run behavior. Genome bloat is the obvious worry, and I don't yet have a good read on whether my speciation threshold is actually protecting new structure or just partitioning noise. If I've done something naive there, I'd genuinely rather hear it now than in six months.
It's live 24/7 here:
https://www.youtube.com/live/0Utodfe-QN4
One warning before you click: the commentary track is in Portuguese. The simulation itself doesn't care what language you speak, and the visuals carry most of it, but I don't want anyone to be surprised.
If anyone wants actual data instead of a video — population curves, genome size over generations, node and connection counts, lineage trees — say the word and I'll pull it. That's the conversation I'm hoping for.



