|
|
|
Biogeography
Biogeography, also known as geographic distribution, is the study of the geographical distribution of organisms worldwide. Animals vary widely in their tolerance of environmental conditions and thus many types of animals exist. Another reason why many types of varieties exist is because of the different environmental conditions around the world. Such variety demonstrates animals’ capabilities in adapting to different conditions around the world.
There are about 1,500 species of Drosophila, the vinegar flies around the world and nearly a third of them live in Hawaii only, despite the fact that the Hawaiian archipelago is so small. There are also more than thousand species of snails and other mollusks that exist solely in Hawaii. The Hawaiian islands are isolated and this probably explains biogeography in terms of evolution (having few colonisers). There were few, if not no predators around which would cause these flies to escape or be extinct and thus the reason for the isolation to hawaii.