biogeografin

Biogeography is the scientific study of the spatial distribution of living organisms across the Earth, integrating ecological, geological, and evolutionary perspectives. It seeks to explain why species occur where they do, how their ranges change over time, and how historical events such as climate shifts and continental drift shape present-day biodiversity.

The field encompasses several subareas. Historical biogeography reconstructs past distributions and the roles of vicariance and dispersal in shaping lineages. Ecological biogeography focuses on how current environmental factors, including climate, vegetation, and interactions with other species, determine where organisms live. Island biogeography, a key theoretical framework, models species richness on islands as a balance between colonization and extinction relative to island size and isolation. Phylogeography combines phylogenetics with geography to study population histories and movements.

Key concepts include patterns of endemism and cosmopolitan distributions, the latitudinal diversity gradient (the tendency for higher species richness in the tropics), and the division of the world into biogeographic realms or provinces (for example, Nearctic, Palearctic, Neotropical, Afrotropical, Indomalayan, Australasian, and Oceanian). Biogeography also examines mechanisms such as vicariance, where barriers split populations, and long-distance dispersal that connects distant regions, as well as the species–area relationship.

Methods used in biogeography include fossil records, comparative anatomy and phylogenetics, contemporary species distribution data, geographic information systems (GIS), and climate and ecological niche modeling. These tools help test hypotheses about historical connections between landmasses and forecast how distributions may shift under climate change or human influence.

Applications of biogeography include informing conservation planning, assessing regional biodiversity, monitoring invasive species, and understanding responses to environmental change. The field has deep historical roots and continues to integrate new data and methods from genetics, ecology, and earth science.