second review round: tempered claims, robust statistics, corrected technical statements

Analyses (figures/stats_llm_epistasis.py, committed + reproducible):
condition-clustered bootstrap CIs (functional measures exclude zero:
dis_raw [+0.04,+0.69], conf-weighted [+0.02,+0.68]; gradient alignment
[-0.59,-0.06]; geometry straddles zero), PAIRED predictor contrasts (not
individually significant — stated), leave-one-condition-out held-out
prediction (functional replicates, geometry ~0, performance baseline
unstable), three outcome references (ordering sensitive to reference —
reported, with the mechanism), between/within-axis decomposition
(within-conflict identification impossible by design; the compat axis
identifies), and seed-level paired reliability (routing/directed beat
soup 3/3 seeds incl. one catastrophic soup failure; CI-width fragility
claim withdrawn).

Renames and corrections: "decisive experiment" -> "controlled predictive
test"; "operational epistasis" -> "confidence-weighted functional
conflict (proposed proxy)"; "functional by construction" -> "controls a
major source of coordinate mismatch / conflict-associated" (module,
configs, READMEs, figures); SI proposition's "chord" defined precisely
(endpoint-loss interpolation, invariant) vs the path (not invariant) +
no-global-optimality caveat (removable = lower bound, residual = upper);
snowball count != performance cliff distinction added; claims table
gains four rows (grid finding / weighting NOT supported / functional-vs-
all-geometry not established / operator choice open); §1 ladder states
the prediction rung as a bounded small-model result.

paper/response-to-review-2.md: point-by-point, opening with the
bookkeeping correction (E13b/c were in the reviewed draft — revised
interpretation, not new results). READMEs rewritten around the four
analyses with the chronology (prospective/adaptive/post-hoc) disclosed.
151 tests green.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BkRLcc18rwT2Lysu6PbG7v

paper/the-evolution-of-sex-for-ai.md

@@ -164,10 +164,15 @@ different things are easily conflated: **interpretation** (an existing result is
 in these terms — e.g., merged offspring beating their parents as Fisher–Muller), **explanation** (the
 transferred mechanism accounts for observations existing accounts leave open — e.g., which merge
 failures are coordinate artefacts and which are functional), and **prediction** (the framework
-forecasts an unmeasured outcome and improves a design decision — e.g., an epistasis measure taken
-*before* merging that beats geometry-based predictors of merge success). This paper is strongest on
-the first, makes concrete progress on the second, and states the third as its open, decisive test —
-proposed here with pre-registered falsifiers, not claimed as done. The organising shift we argue for
+forecasts an unmeasured outcome and improves a design decision). This paper is strongest on the
+first, makes concrete progress on the second, and reports a first, bounded step on the third: a
+**controlled predictive test** at small scale in which pre-merge *functional-disagreement* measures —
+chosen by the framework — showed a detectable, held-out-robust association with merge damage on a
+constructed task grid, while the selected weight-geometry baselines did not. We are precise about
+that result's boundary where it is reported: it is a small-model demonstration on a constructed grid;
+the proposed epistasis-specific refinement did not outperform plain disagreement; predictor
+differences are not individually significant head-to-head; and whether the prediction improves a
+budget-matched operator choice remains open. The organising shift we argue for
 is prior to any single mechanism: **treat multigenerational model populations as systems whose
 inheritance, diversity, and compatibility must be managed — not merely as collections of models to
 optimise.**
@@ -470,9 +475,15 @@ cannot satisfy two contradictory answer conventions — is information-theoretic
 genetics; what the genetic frame adds is *structure around it*: which divergences generate such
 conflicts, the prediction that epistasis rather than distance sets the cliff's position, and the
 snowball's super-linear onset — the latter two verified so far only in the analytic model, and
-therefore carried as **hypotheses at the neural tier, not results**. Second, our alignment removes the
-symmetries we enumerate for this architecture class; richer transformation families for other
-architectures could reapportion removable vs residual, though not below the conflict floor. Third,
+therefore carried as **hypotheses at the neural tier, not results**. (On the snowball, one more
+distinction: super-linear growth in the *number* of incompatibilities does not by itself entail a
+sharp *performance* cliff — that needs the link from incompatibility count through effect sizes to
+measured performance, which the analytic model supplies under its assumptions and any neural test
+must establish separately.) Second, our alignment removes the symmetries we enumerate for this
+architecture class, and exactly recovering a permuted-and-rescaled copy validates a special case
+rather than proving global optimality for independently trained networks — so the removable share is
+a lower bound and the residual an upper bound; richer transformation families for other architectures
+could reapportion the split, though not below the conflict floor. Third,
 "unmergeable" here means by aligned linear interpolation of weights — a barrier to that operator does
 not preclude every conceivable recombination method (routing, for one, sidesteps it by not blending).
 Emergent Dobzhansky–Muller incompatibilities in real weights remain the flagship *hypothesis* of this
@@ -770,7 +781,10 @@ falsifier, not yet established):
 | Outbreeding depression on rugged landscapes; operator design rule | Exact-model result; hypothesis at LLM scale | NK epistasis stands in for skill entanglement | E9–E10; directed selection rescues | Not yet mapped onto a real task-entanglement measure |
 | Optimal mate-pool breadth shrinks with ruggedness | Exact-model result; hypothesis for merging populations | Ring population, local selection | E14 | Phenomenon known to island-model evolutionary computation; our contribution is the mapping and the diversity/mean decomposition |
 | Merge failure decomposes into coordinate artefact + functional residual | Empirical (MLP tier; LLM tier in progress) | Alignment enumerates the architecture's unit symmetries | Full-symmetry residual ≈ 0 (compatible) vs ≈ naive (conflict); cliff in hybrid fitness | Scoped to aligned linear interpolation; conflict floor is information-theoretic, not genetic |
-| Epistasis (not divergence) sets the cliff; snowball onset | Exact-model result; **hypothesis** at the neural tier | BDM incompatibility structure | E12 | The decisive pre-merge prediction test is proposed, not run |
+| Epistasis (not divergence) sets the cliff; snowball onset | Exact-model result; **hypothesis** at the neural tier | BDM incompatibility structure | E12 | Snowball count ≠ performance cliff without the effect-size link; neural test outstanding |
+| Pre-merge functional disagreement predicts merge penalty | Empirical, within a controlled grid (0.5B, 13 conditions × 3 seeds) | Constructed conflict/overlap/duration axes; oracle-potential outcome (pre-registered; ordering sensitive to reference) | Clustered CIs exclude 0; held-out LOCO ρ≈0.4; selected geometry baselines ≈ 0 | Head-to-head predictor differences not individually significant; only selected baselines; generalisation to real task pairs open |
+| Confidence weighting improves rank prediction over raw disagreement | **Not supported** (pre-registered internal prediction) | — | Paired Δ\|ρ\| ≈ −0.02, CI [−0.13, +0.06] | Weighting does double the conflict-vs-compat level contrast |
+| The predictor improves budget-matched operator choice | **Open** | — | Soup-vs-route gap readout noise-dominated at 0.5B | The practical payoff; untested |
 | Emergent speciation without conflict | **Not observed** (pre-registered) | Shared ancestry, compatible tasks, tested divergences | E13b: residual 0.000; merge rescues specialists | Bounds the hypothesis; longer horizons/distribution shift/capacity pressure untested |
 | Grounding + sex + diversity jointly necessary | Exact-model result; hypothesis at LLM scale | Conformity stands in for self-consumption | E11 four-arm ablation, each arm failing distinctly | The full grounded LLM society is unbuilt |