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A4.2.8—EDGE of Existence programme

The EDGE programme prioritizes species that are both globally endangered and evolutionarily distinct, protecting disproportionate evolutionary history from permanent loss.

Syllabus
First assessment 2025
Objective
A4.2.8
Level
SL

Exam analysis

Chance of appearing1%of analysed past papers
Latest appearanceNovember 2025
Most common paperPaper1A
Typical marks1–2

Common command terms

  • Outline
  • Describe

Scoring notes

Common mistake
Explaining EDGE only by expanding the initials without linking distinctiveness to extinction risk.

Recent exam appearances

November 2025Paper1A ["SL"] · TZ322[ 1 ]A4.2.8—EDGE of Existence programme
May 2025Paper2 ["SL"] · TZ33(a)[ 2 ]A4.2.8—EDGE of Existence programme
Practice this objective

Coverage 2025–2025 · Updated 15 Jul 2026

Concept essentials

  • EDGE species are both evolutionarily distinct and globally endangered.
  • Few close relatives means extinction would remove a large amount of unique evolutionary history.
  • EDGE rankings help set conservation priorities for irreplaceable lineages.
  • The programme links phylogenetic information with practical conservation action.
ConceptIB Biology SL