## Problem 169 — rank:159

**Title:** Mutation-rate evolution

**Added binding assumptions (LaTeX):**

```latex
Fix the resident stationary or quasi-stationary state and normalize relative invasion growth accordingly. A drift-limited near-neutral set need not contain a single optimizing mutation rate, and finite mutation among modifiers can produce a distribution rather than a point equilibrium. The neutral fixation baseline is the stated census-copy count only under exchangeable neutral reproduction. Define which changes count as fidelity improvements independently of their total fitness effect.
```

**Direct edits:** 0. **Fresh external checks:** None; supplied sources retained as provenance.