## Problem 144 — rank:32

**Title:** Origin of sexual reproduction

**Added binding assumptions (LaTeX):**

```latex
Define invasion growth relative to the resident demographic normalization, so a neutral modifier has exponent zero. State the stationary-ergodic assumptions for existence of the growth exponent and distinguish the infinite-population rare-lineage approximation from finite-population establishment. A modifier-invasion result addresses maintenance or local origin of sex in that model, not the historical origin of sexual reproduction in all lineages.
```

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