Code and data associated with "The evolution of sex for artificial intelligence - A population-genetic framework for multigenerational model populations". Gilestro, 2026
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Giorgio Gilestro 1721d047fa Layer 1 complete: E3-E6 + E2 analysis add-ons
Finishes the Layer 1 analytical core. All six experiments run with honest,
publication-quality figures; 71 tests green.

- E3 region-matched grounding: `grounding.exercised` knob + per-region tail
  survival. Matched holds the exercised region's tail (0.49) where uniform
  spreads thin and lets it collapse (0.07).
- E4 multi-teacher recombination: `run_coverage` runner. Union coverage matches
  U(K_T,rho,q) exactly. Finding: mean-mixture distillation shows NO surviving
  benefit (a conservation law — 1/K_T dilution cancels the union gain); a
  union-preserving max-merge (M2N2-style) does. E4 reports both operators.
- E5 QD vs greedy: greedy drives fixation (H~0.01); QD holds H at 0.48-0.88,
  rising with the novelty exponent.
- E6 re-mint gate: `arm` multi-override sweep. Re-minting a collapsed lineage
  locks in divergence of KL-to-original; gating on diversity prevents it.
- E2 analysis add-ons (from the companion work order, numbers verified): new
  analysis.py (reduce_to_stationary, critical_grounding with bootstrap CI ->
  g*=0.048, 95% CI [0.047,0.050]); tail_band_metrics + per-band logging; the
  E2 figure rebuilt as a 2x2 (defined g*+CI, g=0 flagged as a finite-time
  artifact, tail item-vs-mass, per-rarity-band panel). Uses truth-mass-weighted
  tail coverage rather than the raw (martingale) tail_mass.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-07-04 18:54:42 +02:00
configs/layer1 Layer 1 complete: E3-E6 + E2 analysis add-ons 2026-07-04 18:54:42 +02:00
figures Layer 1 complete: E3-E6 + E2 analysis add-ons 2026-07-04 18:54:42 +02:00
paper Layer 1 core: Wright-Fisher knowledge-transmission model with E1-E2 2026-07-04 18:10:18 +02:00
results Layer 1 complete: E3-E6 + E2 analysis add-ons 2026-07-04 18:54:42 +02:00
src/knowledge Layer 1 complete: E3-E6 + E2 analysis add-ons 2026-07-04 18:54:42 +02:00
tasks Layer 1 complete: E3-E6 + E2 analysis add-ons 2026-07-04 18:54:42 +02:00
tests Layer 1 complete: E3-E6 + E2 analysis add-ons 2026-07-04 18:54:42 +02:00
.gitignore Layer 1 core: Wright-Fisher knowledge-transmission model with E1-E2 2026-07-04 18:10:18 +02:00
CLAUDE.md Layer 1 complete: E3-E6 + E2 analysis add-ons 2026-07-04 18:54:42 +02:00
Makefile Layer 1 complete: E3-E6 + E2 analysis add-ons 2026-07-04 18:54:42 +02:00
pyproject.toml Layer 1 core: Wright-Fisher knowledge-transmission model with E1-E2 2026-07-04 18:10:18 +02:00
README.md Layer 1 core: Wright-Fisher knowledge-transmission model with E1-E2 2026-07-04 18:10:18 +02:00
uv.lock Layer 1 core: Wright-Fisher knowledge-transmission model with E1-E2 2026-07-04 18:10:18 +02:00

The Lamarckian Society — Layer 1 (analytical core)

A parametric population-genetics model of knowledge transmission across generations of learning agents. Knowledge transmission is modelled literally as a WrightFisher process (not by analogy): a model's knowledge is a distribution p_t over K discrete items; a fixed true distribution p* has a rare tail; each generational step is "sample from the parent (drift) + mix in fresh real samples (grounding/immigration) + refit." Model collapse is the loss of rare alleles under drift.

See paper/blueprint.md (the normative build spec) and paper/the-lamarckian-society-v4.md (the perspective paper).

Reproduce

Environment is a uv venv built from the committed, hash-pinned uv.lock — that lockfile is the single source of truth for "it runs" (Layer 1 is pure NumPy/SciPy and bitwise-reproducible from a seed; no container needed).

# one-time: install uv (https://astral.sh/uv)
curl -LsSf https://astral.sh/uv/install.sh | sh

uv sync                 # build .venv from uv.lock
make test               # correctness + scientific-validation tests (the spine of trust)
make layer1             # run experiments E1E6
make figures            # regenerate figures from committed results

Layout

src/knowledge/   Layer 1 package (imported as `knowledge`)
configs/layer1/  one YAML per experiment (E1..E6)
figures/         plot_EX.py — read results.parquet only
tests/           test_correctness.py + test_scientific_validation.py (analytic checks)
paper/           blueprint.md, perspective paper, figure_manifest.md
results/         written artifacts (gitignored; hashes tracked in manifest.json)