Theory of Biogeography

Biogeography is the study of the distribution of species and the factors that influence their distribution.

Island Biogeography

Island biogeography is a theory that explains the factors that influence the number of species on an island. The theory was developed by Robert MacArthur and Edward O. Wilson in the 1960s.

According to island biogeography theory, the number of species on an island is influenced by two factors: the size of the island and its distance from the mainland. Larger islands have more resources and can support more species, while islands that are closer to the mainland are more likely to receive colonizers from the mainland, increasing the number of species on the island.

Island biogeography theory has important implications for conservation biology, as it highlights the importance of protecting larger and more isolated habitats in order to preserve biodiversity.

Ecological Biogeography

Ecological biogeography is the study of the distribution of species in relation to their physical and biological environment. This field of study examines the factors that influence the distribution of species, including climate, geology, and topography.

One of the key concepts in ecological biogeography is the idea of biomes, which are large-scale ecological communities that are defined by their dominant vegetation and climate. Examples of biomes include tropical rainforests, deserts, and tundra.

Ecological biogeography also examines the factors that influence the distribution of individual species, such as their tolerance for different environmental conditions and their ability to disperse across different habitats.

Historical Biogeography

Historical biogeography is the study of the distribution of species in relation to their evolutionary history. This field of study examines the historical events and processes that have influenced the distribution of species, such as continental drift and glaciation.

Historical biogeography also examines the patterns of diversification among different groups of organisms, such as the rapid diversification of mammals after the extinction of the dinosaurs.

Phylogeography

Phylogeography is a subfield of biogeography that uses genetic data to study the historical processes that have influenced the distribution of species. This field of study examines the patterns of genetic diversity within and between populations, and uses this information to infer historical events such as population expansions and contractions.

Phylogeography has important implications for conservation biology, as it can be used to identify genetically distinct populations and prioritize conservation efforts for those populations.

Implications for Conservation Biology

The theory of biogeography has important implications for conservation biology, as it highlights the factors that shape the distribution of species and the processes that influence their evolution. Understanding these factors is essential for effective conservation planning and management.

For example, island biogeography theory suggests that larger and more isolated habitats are more likely to support a greater number of species, and should therefore be prioritized for conservation. Ecological biogeography suggests that conservation efforts should focus on protecting a diversity of habitats and biomes, in order to preserve the full range of biodiversity.

Historical biogeography and phylogeography can be used to identify genetically distinct populations and prioritize conservation efforts for those populations. This information can be used to inform the design of protected areas and other conservation strategies.