biogeographies

Biogeography is the scientific study of the distribution of organisms across geographic space and through time. It seeks to explain why particular species occur where they do, how regional faunas and floras are assembled, and how historical events and ecological processes shape current patterns. The plural form “biogeographies” is used to refer both to geographic patterns of life and to the subfields that study them.

Dispersal, vicariance, and extinction are key processes. Dispersal moves organisms between areas; vicariance splits ranges by barriers such as mountains or oceans; extinction removes populations; these processes interact with climate change, geological changes, and habitat fragmentation to produce current distributions. Island biogeography and the concept of endemism illustrate how geography and area affect species richness and assembly.

Biogeography includes several subfields: ecological biogeography focuses on present-day distributions and environmental correlates; historical biogeography investigates how past events shaped lineages; and phylogeography combines phylogenetics with geographic information to infer historical processes. Methods include species distribution modeling, comparative phylogeography, fossil records, and GIS-based analyses; the theory of plate tectonics provides a broad temporal framework.

In practice, biogeography informs conservation, biodiversity assessment, and climate-change studies by predicting where species are likely to occur under changing conditions and identifying biogeographic regions and corridors essential for maintaining ecosystems.

Historically, biogeography developed from observations by naturalists such as Humboldt and Wallace, and it has grown with advances in paleontology, genetics, and spatial analysis.