Breeding

Breeding is the construction of one new organism in the Rorschach Lab: a single operator is chosen, applied to zero, one or two living parents, and the resulting genome is either stored or thrown away. Six operators are in rotation, three of them pure code that returns in milliseconds and three of them a call to a model. One birth is attempted per track per pass of the loop, and a birth that is rejected leaves nothing behind.

Parent selection

The breeding pool for a track is every living organism whose code has rendered at least once. If no living organism in the track has rendered, the pool falls back to the whole living set.

With fewer than two organisms in the pool, the operator is always fresh and no parent is picked at all. Otherwise the first parent comes from one of two tournaments, both of which sample three organisms at random from the pool:

• The rating tournament keeps the sampled organism with the highest fitness. This is the default path.
• The novelty tournament keeps the sampled organism whose nearest neighbour in the pool is farthest away, which is the outlier rather than the champion. It fires on a probability held in lab.config.json, and only once the pool holds at least four organisms.

A two-parent operator picks a partner from the rest of the pool. Phylum fidelity applies first: on a configured probability the candidate list is narrowed to organisms sharing the first parent’s phylum, and the narrowing is skipped when that phylum has no other members. That probability drops to a second, much lower configured value while the track is in a diversity crisis, so an inbred pool is pushed to outcross. The remaining candidates are ranked by token distance from the first parent, farthest first, and one of the top four is taken at random. A one-parent child inherits its first parent’s phylum, so a two-parent birth that crosses phyla is the only event that mixes lineages.

The operator set

The weights below are the lab’s current configuration in lab.config.json and are drawn as a cumulative roulette; a roll past the last weight yields mutate. In a diversity crisis a share of passes bypasses the roulette entirely and takes fresh, which is the only operator that can add a lineage rather than enlarge one.

A free operator is jitter, splice or graft. What counts as a locus and as an allele differs by track:

A structural operator is often inapplicable, since two parents may share no swappable locus and a panel may hold too few rules to pair. Rather than lose the pass, the code retries with jitter, and abandons the birth only if jitter also finds no allele to move. A free operator consults no prompt gene: its child keeps the first parent’s directive and the first parent’s title.

A model operator selects a living prompt gene for the track first, and abandons the birth if the track has none. The prompt sent to the model is the track’s fixed contract, then the directive, then the parents’ full source. The axes a mutate or crossover must move along are drawn at random from a fixed list of fourteen per track. fresh is additionally handed short labels for up to fourteen of the pool’s current organisms, ordered by fitness, and told that a near-duplicate of any of them is worthless.

The model runs as one headless turn with no tools available to it. The reply’s last fenced code block becomes the genome; a leading TITLE: line, if present, becomes the title, truncated to 60 characters. A call that fails or exceeds the configured timeout is logged as a failed birth and the pass produces nothing.

Radical mutation

A mutate roll has a second roll inside it. On a probability held in lab.config.json, doubled while the track is in a diversity crisis, the operator becomes a radical mutation: the model is told to keep only the single element it considers the parent’s best idea, rebuild everything else around it, move to the opposite end of three axes rather than two, and produce something that could not be confused with the parent at a glance. Like fresh, a radical mutation receives the pool labels to avoid, so the jump lands away from occupied territory.

A radical child is recorded under the operator name radical, not mutate, so the branch is visible in the birth record afterwards.

Inheritance

Inheriting the parents’ rating rather than starting at the midpoint means a child is not made to re-earn its lineage’s standing from zero, and it means an unjudged child is ranked at its parents’ level until judging moves it.

Rejection at birth

A candidate genome is discarded, with the reason logged, on any of these:

• It fails the track’s contract.
• Its code is byte-identical to a parent’s. A free operator produces this whenever the jitter lands on nothing that matters.
• It came from fresh and sits within the minimum fresh distance of some organism already in the pool.
• It came from a model operator and sits within the minimum child distance of one of its parents.
• It would join a clone family already at its cap.

Free operators are exempt from the parent-distance test. Token distance ignores numeric literals, so a jittered child measures zero from its parent by construction and the test would reject every one of them; the clone family cap still applies.

The breeding loop

The daemon runs one pass over the configured tracks in order, then sleeps. Within a pass, each track is handled in sequence:

1. Culling runs, so the gate below reads the pool that culling leaves behind.
2. The living organisms in the track with no game on either ladder are counted. At or above the configured backlog limit, the track is skipped for this pass.
3. One birth is attempted. Culling runs again.
4. Prompt evolution runs for the track when the shared birth counter reaches its next threshold, on the cadence prompt genes sets out.

Breeding never halts on population size. The only thing that stops it is the judging backlog, since death rather than a pause in births is what holds the pool at its carrying capacity.

The pass sleeps 400 ms when any track recorded a birth and the configured idle interval when none did. Free operators return in milliseconds, and a full idle sleep after one would spend the entire speed advantage of not having called a model.