Biogeography is the study of the distribution of species, ecosystems, and genetic diversity in geographic space and through geological time. It seeks to answer questions like: Why are certain species found in one part of the world and not another? What historical and ecological factors have shaped the patterns of life we see today? The field examines how factors like climate, topography, and continental drift influence the dispersal, evolution, and extinction of organisms.
The scientific foundations of biogeography were laid in the 19th century by naturalists who traveled the globe observing and documenting life. Alexander von Humboldt, often called the "father of phytogeography," systematically documented how plant life changed with elevation and climate. Alfred Russel Wallace, a co-discoverer of the theory of evolution by natural selection, is considered the "father of zoogeography." His work in the Malay Archipelago led him to identify a distinct boundary, now known as the Wallace Line, separating the fauna of Asia and Australia.
Biogeography is a highly integrative science, drawing on ecology, evolutionary biology, geology, paleontology, and climatology. It has critical modern applications, especially in conservation biology. By understanding the historical and current distribution of species, scientists can design more effective conservation areas, predict how climate change will cause species ranges to shift, and manage the spread of invasive species. It provides the essential context for understanding global biodiversity and the threats it faces.