biogeography

Biogeography is the scientific study of the spatial distribution of organisms across the Earth and through time. It seeks to explain patterns of where species occur, how they are arranged within ecosystems, and the historical and ecological processes that produce these patterns. The field integrates data from ecology, evolution, geology, climatology, and paleontology to understand biodiversity in space and time.

Historically, biogeography emerged from natural history and exploration in the 18th and 19th centuries, with contributors such as Alexander von Humboldt and Alfred Russel Wallace shaping ideas about the relationship between geography and life. The modern discipline incorporates plate tectonics, climate change, dispersal, and vicariance, and island biogeography became a central model through the work of MacArthur and Wilson, linking island size, isolation, and species richness to colonization and extinction dynamics.

Methods and approaches combine field surveys, fossil records, and phylogenetic analyses to infer historical distributions, together with molecular dating and biogeographic models. Geographic information systems (GIS), species distribution modeling, and comparative methods support the reconstruction of ancestral ranges and the prediction of future shifts under climate change.

Subfields include historical biogeography, ecological biogeography, island biogeography, conservation biogeography, and phylogeography. Key concepts encompass endemism, biogeographic realms, the latitudinal diversity gradient, the species–area relationship, and refugia. Biogeography informs conservation planning, biodiversity assessments, and forecasts of how distributions may respond to environmental change.