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 db9452c9d4 E12: model speciation — the merge-compatibility limit of the sexual society
New analytic result for the evolution-of-sex paper: how far can two lineages
diverge before recombination (model merging) stops working? Frames merge failure
as biological reproductive isolation via Bateson-Dobzhansky-Muller
incompatibilities. src/knowledge/speciation.py, kind: speciation, on the E7-E11
genotype machinery (pure seeded NumPy, bitwise-reproducible; no external
simulator whose separate RNG would break that).

- BDM construction (E12.yaml): ancestor + two lineages substituting disjoint loci
  (each parent adaptive, incompatibility-free), a fraction rho of cross-lineage
  pairs are BDMIs. Sweeping divergence d reproduces the predicted
  compatible -> outbreeding depression -> hybrid inviability curve; the isolation
  cliff moves to lower d as epistasis density rises (iso at d=20: 0.00/0.03/0.50
  for rho 0.1/0.25/0.5); incompatibilities snowball ~ (d/2)^2 (Orr-Turelli).
- NK variant (E12_nk.yaml): parents = hill-climbed local optima; the epistasis
  wedge — recombination gain flips 0 -> -0.13 and OD rate 0 -> 0.90 as ruggedness
  K rises. At matched divergence, mergeability is governed by epistasis, the axis
  no divergence-only ML merge predictor captures.

plot_E12.py (3-panel), +7 tests (138 green), README with honest positioning
(concedes the empirical phenomenon to Pari 2024 / Zhou 2026 + permutation
artefacts to Git Re-Basin; claims the predictive theory + the epistasis wedge).
Wired into make layer1.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2026-07-08 22:40:02 +01:00
configs E12: model speciation — the merge-compatibility limit of the sexual society 2026-07-08 22:40:02 +01:00
figures E12: model speciation — the merge-compatibility limit of the sexual society 2026-07-08 22:40:02 +01:00
hpc hard benchmark: the 7B "fusion wins / no headroom" results were saturation artefacts 2026-07-05 19:13:26 +01:00
paper papers: consolidate the real-LLM recombination arc (merge/moe/directed + headroom law) 2026-07-05 19:20:19 +01:00
results E12: model speciation — the merge-compatibility limit of the sexual society 2026-07-08 22:40:02 +01:00
src E12: model speciation — the merge-compatibility limit of the sexual society 2026-07-08 22:40:02 +01:00
tasks hard benchmark: the 7B "fusion wins / no headroom" results were saturation artefacts 2026-07-05 19:13:26 +01:00
tests E12: model speciation — the merge-compatibility limit of the sexual society 2026-07-08 22:40:02 +01:00
.gitignore neural: real-MNIST external-validity tier (collapse + grounding) 2026-07-05 09:19:36 +01:00
CLAUDE.md hard benchmark: the 7B "fusion wins / no headroom" results were saturation artefacts 2026-07-05 19:13:26 +01:00
Makefile E12: model speciation — the merge-compatibility limit of the sexual society 2026-07-08 22:40:02 +01:00
pyproject.toml llm: first real-LLM prototype — recombining specialist LLMs (C2/C4) 2026-07-05 15:48:02 +01:00
README.md paper: reframe the perspective paper around sexual reproduction (v4 -> v5) 2026-07-05 13:53:10 +01:00
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), paper/the-lamarckian-society-v5.md (the perspective paper), and paper/results-summary.md (a summary of all results).

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)