## Problem 293 — rank:192

**Title:** The lipid divide

**Added binding assumptions (LaTeX):**

```latex
Include the hereditary biosynthetic state and resource requirements in the transition state, not only the lipid-composition vector. A viable physical mixture may lack an accessible biosynthetic route, while an experimentally constructed route establishes possibility rather than ancestry. Fix the admissible step library and environmental schedule. Historical inference must propagate homology, transfer and ancestral-state uncertainty separately from membrane-physics viability tests.
```

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