Biogeography is the study of the distribution of species and ecosystems in geographic space and through geological time. Organisms and biological communities often vary in a regular fashion along geographic gradients of latitude, elevation, isolation and habitat area. Biogeography, the study of the geographic distribution of plants, animals, and other forms of life. It is concerned not only with habitation patterns but also with the factors responsible for variations in distribution. Biogeographic studies divide Earth’s surface—primarily the continents and islands—into regions exhibiting differences in the average composition of flora and fauna. It is thought that the present-day distribution patterns of plant and animal forms, as reflected in such biogeographic regions, are the result of many historical and current causes. These causes include present climatic and geographic conditions, the geologic history of the landmasses and their climates, and the evolution of the taxon (e.g., genus or species) involved. Investigators have found that rate of dispersal, adaptability to prevailing environmental conditions, and