Biogeographic regions, identified originally by the English ornithologist Philip L. Sclater (1829-1913) and German botanist H.G. Adolf Engler (1844-1930), are large areas with particular flora and fauna, due to their isolation during continental drift.

English naturalist Alfred Russell Wallace (1823-1913), contributed greatly to biogeography with his book "The Geographic Distribution of Animals" in 1876.

Originally, six regions were identified: Palearctic (Europe and Asia), Nearctic (North America), Neotropical (Mexico, Central and South America), Ethiopian (Africa), Indian (Southeast Asia, Indonesia) and Australian (Australia and New Guinea). Currently, eight are recognised since the addition of Oceania (Polynesia, Fiji and Micronesia) and Antarctica.

Mexico is on the boundary between two biogeographic regions, the Nearctic and Neotropical, which contributes to its great natural richness.