About this document

This document is an editorial assembly of five separately researched chapters. Nothing factual has been added, altered or resolved during assembly: the editor’s job was confined to rearranging, deduplicating and smoothing. Where chapters repeat material, the fullest version was kept in its best home and the duplicate replaced with a cross-reference; where chapters contradict each other, both claims were kept and the conflict is flagged in the dedicated Unresolved Conflicts section rather than adjudicated. Anything that looked like a research error was left as found and listed under Editor’s Queries.

Conventions carried over from the source chapters:

• Every claim carries an evidence tag: peer-reviewed, preprint / trial, citizen science, community report, historical (Part V also uses official / policy for government and regulatory documents). Community reports are never discarded for being anecdotal — they are labelled honestly and included because patterns in anecdote are data.
• Where sources conflict, the conflict is presented explicitly rather than smoothed over. “Unknown” and “contested” are treated as valid, final answers where that is what the evidence supports.
• Section numbers restart within each part and are retained unchanged from the source chapters. Internal cross-references of the form “§x.y” refer to sections within the same part unless another part is named. Pointers added during assembly are always marked (Editor’s note: …).
• All diagrams and tables are retained as found. No two diagrams from different chapters merged cleanly, so none were combined.
• Parts IV, V and VI keep their own reference lists (retitled “References (Part …)”); Parts I–III and VII cite sources inline.