Which study deals with the geographical distribution of plants and animals?

Biogeography is the study of how species are distributed. It notes where organisms live, and why they are (or are not) found in a certain geographical area. Biogeography teaches how animals and plants are adapted to the places they live in, and how similar places often have quite different animals and plants.

New species are usually formed by speciation – an earlier species splitting into two. These species may travel to new places. but they may be stopped from travelling by mountains and seas, and by climate. This means that "two places with similar climate often have different kinds of animals and plants". For example "marsupials", which live in Australia, are very different from the fauna in South America. The species on islands (Hawaii, Galapagos) may be very different to species on mainland continents.