# E13b — Emergent divergence (no imposed conflict): does model speciation arise spontaneously?

Companion to `results/speciation_real/` (full legend and interpretation there; figure panel C of
`speciation_real.png`). Pre-registered design: `shared` control, `disjoint` (complementary class
specialists 0–4 vs 5–9), `augment` (same labels, inputs rolled ±3 px) — **no conflicting training
signal anywhere** — swept over post-fork divergence `t_div ∈ [100, 3200]`, 4 replicates, with
alignment modulo the full ReLU unit symmetry group (E13c).

**Outcome (the pre-registered second reading):** residual barrier **0.000 at every divergence in both
emergent conditions**; the merged model **rescues** the two forgetting `disjoint` specialists
(parents → 0.535/0.474; merge ≈ 0.955 throughout — a sustained Fisher–Muller rescue at zero barrier).
**Speciation requires functional conflict; it does not emerge from compatible specialisation on shared
ancestry in this regime.** An honest bound on the biological analogy, and a positive design result:
merging complementary specialists of shared ancestry is safe — the danger is conflicting conventions,
not specialisation. LLM-scale over-specialisation is the open tier (`llm_speciation`, PNAS work order
Phase 3).