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 0f7b775ae5 society: the dynamic Lamarckian society — the vertical claim (E11 / C3)
The culmination. A finite population of agents (genotypes, L loci) evolves
on a rugged NK landscape that IS reality (knowledge/dynamic_society.py),
composing the four operators the whole study built toward: grounding,
directed recombination (sex), quality-diversity selection, and mutation.
Grounding is made load-bearing via the consensus-conformity (self-
consumption) mechanism (GG decision): selection acts on
g*true_fitness + (1-g)*conformity, where conformity = agreement with the
population's own consensus, so at g=0 the society optimises fitting-the-
crowd rather than reality.

4-arm ablation (12 reps), each breaking distinctly, only the full society
climbing (global_opt ~ 0.79):
- full         0.78  climbs to the optimum, diversity maintained longest
- no_sex       0.77  can't recombine to escape local optima
- no_diversity 0.74  greedy: collapses diversity fastest, worse local optimum
- no_grounding 0.48  self-consumption collapse to an unfit consensus
                     (trains on the crowd -> confident-but-wrong mean;
                      conformity-true gap ~ 0.5)

This integrates E1-E6 + the learning kernel + E7-E10 into one system and
shows the Lamarckian society needs ALL of grounding + directed sex +
diversity: on a rugged landscape you need diversity to explore basins, sex
to recombine them, and grounding to select on reality -- remove any one and
you fail differently. Closes the C3 vertical claim analytically; the LLM
rung remains the eventual empirical instantiation.

New: knowledge/dynamic_society.py, configs/layer1/E11.yaml, figures/
plot_E11.py, README, tests/test_dynamic_society.py (+5). kind:
dynamic_society dispatch; make layer1 wired. 122 tests green.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2026-07-05 12:34:01 +01:00
configs society: the dynamic Lamarckian society — the vertical claim (E11 / C3) 2026-07-05 12:34:01 +01:00
figures society: the dynamic Lamarckian society — the vertical claim (E11 / C3) 2026-07-05 12:34:01 +01:00
paper Layer 1.5: architecture-general neural existence proof 2026-07-04 21:02:49 +01:00
results society: the dynamic Lamarckian society — the vertical claim (E11 / C3) 2026-07-05 12:34:01 +01:00
src society: the dynamic Lamarckian society — the vertical claim (E11 / C3) 2026-07-05 12:34:01 +01:00
tasks society: the dynamic Lamarckian society — the vertical claim (E11 / C3) 2026-07-05 12:34:01 +01:00
tests society: the dynamic Lamarckian society — the vertical claim (E11 / C3) 2026-07-05 12:34:01 +01:00
.gitignore neural: real-MNIST external-validity tier (collapse + grounding) 2026-07-05 09:19:36 +01:00
CLAUDE.md society: the dynamic Lamarckian society — the vertical claim (E11 / C3) 2026-07-05 12:34:01 +01:00
Makefile society: the dynamic Lamarckian society — the vertical claim (E11 / C3) 2026-07-05 12:34:01 +01:00
pyproject.toml Layer 1.5: architecture-general neural existence proof 2026-07-04 21:02:49 +01:00
README.md Layer 1 core: Wright-Fisher knowledge-transmission model with E1-E2 2026-07-04 18:10:18 +02:00
uv.lock Layer 1.5: architecture-general neural existence proof 2026-07-04 21:02:49 +01:00

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)