Biogeography

From ArticleWorld

Biogeography is a science dealing with the study of the distribution of organisms and the processes that cause the patterns of distribution. Biogeography is a comparative and observational science that formulates theories based on patterns and tests these by observation of natural situations. Historical events also play a major role in biogeography as the distribution of species can be attributed to these events. These include continental drift, extinction and speciation, to name a few.

History

Biogeography dates back a long way and includes studies conducted in the 1700's by Linnaeus and in the 1800's by Wallace and Darwin, where they made observations on the distribution of organisms. Biogeography however benefited greatly from the publication of The Theory of Island Biogeography. This publication opened up the field of biogeography. It showed that rather than being a purely historical field, biogeography could be applied to present day situations by using factors such as habitat area, immigration and extinctions rates to predict species richness.

Biogeography fundamentals

There are several fundamental processes in biogeography. The three major ones are evolution, extinction and dispersal. Evolution may be defined as an irreversible alteration in the genetic composition of a population. Extinction is the permanent elimination of a species. Dispersal is the movement of organisms away from their point of origin. The other fundamental processes include endemic areas and range and distribution of organisms.

Fields of specialization

The biogeographer may focus on certain areas of biogeography. These include: *Phytogeography which studies plants.

• Zoogeography which studies animals.
• Historical biogeography which attempts to determine the origins, dispersal and extinction of organisms.
• Ecological biogeography which studies the present distribution of organisms and plants and their relationship to their environment.

Some fields that overlap with biogeography include geography, biology, ecology, evolution, geology and climatology.