Large beak Depth competitors was introduce
The observation was natural selection could be changeable because it is supported by the various climates the environment have. The number of small-break depth Geospiza fortis grew inferior on an island when a large-beak-depth was originated.
The reason is that the large-beak-depth species has higher durability rate, especially during dry season, where they can consume larger and harder seeds corresponding to the small-beak-depth birds.