Cambridge O Level Biology · Syllabus 5090 · Relationships of Organisms with One Another and with the Environment
Non-native Species
What is Non-native Species?
A species brought by human activity into an area where it does not naturally occur. A non-native species may have no natural predators, parasites or diseases in its new habitat, so its population can grow rapidly; it may compete with native species for food, water, light or space, prey on native organisms, or introduce a disease to which they have no resistance. Where this happens, native populations fall, food webs are disrupted and biodiversity decreases. Many introduced species have little effect, so the outcome is described as possible rather than certain.
This definition is part of the Relationships of Organisms with One Another and with the Environment chapter in Cambridge O Level Biology.
Common mistakes with Non-native Species
- “Every non-native species becomes invasive.” Why it is wrong: most introduced species fail to establish, and many that do have no measurable effect. Exam-safe: an introduced species may compete with, prey on or bring disease to native species, especially if it has no natural predators there.