Biogeography is one of the oldest sub-fields of discipline, concerned with describing and explaining the spatial patterns of the distribution of living organisms: for example where the living organisms are, where they are not and why they are missing there. While this field of study has now become tightly bound up with the rise of scientific and policy effort to manage species extinctions and conserve biological diversity, however, the study of biogeography represents an important and generative common ground between human and physical geographers, both historically, today and future.

The major branch of geography is biogeography or biology which for some reasons may be subdivided along the main division of living things into two kingdoms yielding plant geography (zoogeography) and animal geography (phytogeography), thus biogeography implies the linkages between biology and geography.

It is noteworthy however that both traditionally the study of plant geography (phytogeography) has been distinct from one animal geography (zoogeography). The distinction is artificial for the two are not separate in nature; they are always in the same place.

Definition of Biogeography

Biogeography is defined as the study of distribution of plants and animals on the earth surface, it deals with how these plants and animals are distributed on the earth surface at a particular time and space and certain factors responsible for variation in distribution.

Scope and Nature of Biogeography

Biogeography is closely related to ecology which is the study of the inter-relationships between organisms and their habitat. The organism home or habitat could vary from a small micro habitat such as under a stone or a leaf to Biomes which could be a tropical rainforest or desert. However, biogeography is a broad discipline but has two main branches

1. Ecological Biogeography which is the present distributions and geographic variation in diversity, how biotic and abiotic interactions influence species distributions, interactions between species (e.g., predation and competition).
2. Historical Biogeography which is the second deals with continental drift, glaciation, evolutionary lineages reconstructing the origin, dispersal and speciation and extinction of species.

However, the term biogeography is the study of the geographic patterns of species distribution; it is an aspect of physical geography that examines the physical environment and the way it affects the distributions of various species on the earth surface. The discipline is related to biology, ecology, evolution studies, climatology, and soil sciences as they are relate to animal populations and the factors that allow them to flourish in particular regions of the globe. In that case, we are unable to separate biogeography from its related fields, since biogeography is relying heavily on theory and data from other related subjects.

In the late nineteenth and early twentieth centuries, biogeography was a focus of analysis across disciplines such as geography, anthropology and archaeology, both for those concerned with the development of human societies and for those concerned with the distribution and viability of animal or plant populations.

Biogeography seeks to describe and analyze distributional patterns exhibited by organisms at present and in the past. To enable it to comprehend distributional patterns, biogeography needs to study physical and organic factors as they are now and how they were in time past. To acquire this knowledge, it must use information drawn largely from the natural and earth sciences. It is an interdisciplinary subject within these domains.

Examples of Common Questions in Biogeography

1. Why are various types of organisms seen on the Earth surface?
2. Where have these organisms distributed?
3. What is the reason for the distribution at such places?
4. Why are the tropics so biologically diverse relative to higher latitude regions?
5. Can that diffusion pattern be maintained continuously?
6. Do various changes take place in maintaining it continuously?
7. What are responsible for different changes?
8. Similarly, how will the diffusion patterns change in the future?
9. What are the factors that influence such changes?

Importance of Biogeography

If we accept that the field of biogeography is the study of living things and especially the association of living things, the next question, which poses itself, is for what reason or purpose does a geographer study biogeography? One simple answer to this question of course will be that: A geographer studies biogeography in order to understand and solve biogeographic problems. Other reasons we study biogeography are:

1. Biogeography enables us to identify biodiversity patterns in the past and present, to identify the expansion of organisms while it enables us to study about the relationship between living and non-living factors influence organisms to exist.
2. It enables us to identify the environmental diversities of Biogeography and the fluctuations of diversities and the problems arising in the environment.
3. We study biogeography to find out why resources are not evenly distributed on the Earth
4. It also helps us to find out what is where and why it is there
5. Biogeography provides evidence of evolution

A biogeographer is a person who studies the geographic distribution of plants and animals on the earth.

The study of biogeography became popular due to the work of Alfred Russel Wallace, an England exploraer (1823-1913). Alfred Russel Wallace is regarded as the father of biogeography. Wallace was a naturalist, explorer, geographer, anthropologist, and a biologist who was recorded as the first geographer to extensively study the Amazon River and then the Malay Archipelago (the islands located between the mainland of Southeast Asia and Australia).

During his time in the Malay Archipelago, Wallace studied the flora and fauna and came up with the Wallace Linea line that divides the distribution of animals in Indonesia into different regions according to the climates and conditions of those regions and their inhabitants’ proximity to Asian and Australian wildlife. Those closer to Asia were said to be more related to Asian animals while those close to Australia were more related to the Australian animals. Aside Wallace, there were a number of other biogeographers who also studied the distribution of species, and most of those researchers looked at history for explanations, thus making it a descriptive field. They include

• Carl Linnaeus Georges-Louis Buffon
• Johann Reinhold Forester
• Alexander von Humbolt
• Agutin de Candolle
• Charles Lyell
• Charles Darwin
• Alfred Wegnen
• Ernst Mayr
• G.E. Hutchison
• Robert H. MacArthur
• Edward O. Wilson