A3.1.5—Difficulties in distinguishing species
Distinguishing species can be difficult when populations diverge gradually, hybridize, or show genetic evidence that does not match simple ranges.
- Syllabus
- First assessment 2025
- Objective
- A3.1.5
- Level
- SL
Concept essentials
- Speciation is gradual, so boundaries between diverging populations can be uncertain.
- Genetic data can show whether populations have mixed or remained separate.
- Geographic separation can prevent interbreeding even when organisms remain similar.
- Species classification may require several evidence types rather than one observation.
ConceptIB Biology SL