CAIE IGCSE Biology 18.3.4 Adaptation by Natural Selection
Practise describing adaptation as natural selection making populations better suited to their environment over generations.
- Syllabus
- 2026–2028
- Course
- Biology 0610
Practise describing adaptation as natural selection making populations better suited to their environment over generations.
Fig. 5.1 shows Mackinlay's cuckoo-dove, Macropygia mackinlayi, which is found on most of the islands in the south-west of the Pacific Ocean.

Fig. 5.1
Karkar Island is one island where Mackinlay's cuckoo-dove is found. This species is part of many communities that are adapted to the different habitats on the island.
Complete the passage with the most appropriate word or phrase.
Adaptation is sometimes defined as the process resulting from by which populations become more suited to their over many generations.
natural selection ; environment ;
A mutation