These boundaries often align with geological barriers like oceans, mountain ranges, and vast deserts, which prevent species from migrating and mixing. These large-scale patterns form the foundation of biogeographic realms , the broadest units used to categorize the distribution of the world's ecosystems and organisms.
Biogeographic Realms Historical Development Concept
Life on Earth does not distribute randomly. Over millions of years, isolated populations diverge, leading to unique assemblages of life that define each realm.
The concept of a biogeographic realm emerged from the work of 19th and early 20th-century naturalists who observed sharp transitions in flora and fauna across continents and oceans. This realm is defined by an unparalleled richness of life, including countless plant species, jaguars, harpy eagles, and an immense variety of insects and amphibians.
Biogeographic Realms Historical Development Concept
The Primary Biogeographic Realms Currently, the scientific community generally recognizes eight major biogeographic realms , each representing a unique evolutionary theater. Realm Key Characteristic Iconic Example Nearctic North America Bison and maple forests Palearctic Eurasia and North Africa Snow leopards and boreal forests Neotropical Central and South America Amazon rainforest diversity Afrotropical Sub-Saharan Africa Savannas and primates Indomalayan South and Southeast Asia Tigers and tropical forests Australasian Australia and New Guinea Marsupials and unique flora Oceanian Pacific islands Island endemism Antarctic Antarctica and sub-Antarctic islands Marine mammals and lichens The Neotropical and Afrotropical Realms The Neotropical realm is arguably the most biodiverse region on the planet.
More About Biogeographic realms
Looking at Biogeographic realms from another angle can help expand the discussion and give readers a second clear paragraph under the same section.
More perspective on Biogeographic realms can make the topic easier to follow by connecting earlier points with a few simple takeaways.
