Biogeographical Distribution of Animals Across Global Realms and Regions
Table of Contents
Explore the biogeographical distribution of animals across six major global realms, their regional species diversity, and evolutionary significance.
Introduction
Biogeographical distribution refers to the patterns of where animals live around the world and why they are found in certain places. These patterns are shaped by environmental conditions, historical events like continental drift, and ecological interactions. Understanding this distribution offers key insights into biodiversity, conservation, and evolutionary biology.
This knowledge is vital for ecologists, zoologists, conservationists, and students of life sciences. In this blog post, we delve into the major biogeographical realms of the world, a topic of immense importance in zoological and ecological studies. The focus keyword biogeographical distribution is central to understanding the content that follows, highlighting the relevance of species spread in shaping global biodiversity.
Article
Biogeographical Realms
“The earth has been divided into six major biogeographic regions, called realms on the basis of distribution of animals and plants. Dr. P.L. Sclater in the year 1858 proposed first time the division of the world into six realms or regions according to the distribution of birds. In 1876 A.R. Wallace adopted it for all the animals. These realms (regions) are:”
(i) Palaearctic Realm
“It includes Europe, north of Himalaya, China, Sahara desert of Africa, Siberia and a major part of Asia.
Important Animals: Anabas, Bufo, Rhacophorus, Alytes, Proteus, Necturus, Varanus, Alligator, Hawks, Camel, Tiger, Seal, Panda.”(ii) Oriental Realm
“It includes India, Malaysia, Philippines, Indonesia, Sri Lanka, Myanmar (Burma).
Important Animals: Carps, Cat fishes, Apods, Frogs, Draco, Python, Cobra, King cobra, Crocodile, Gavialis, Peacock, Hornbills, Porcupines, Loris, Gibbon, Rhinoceros, Elephants, Tiger, Lion.”(iii) Australian Realm
“It covers Australia, New Zealand, New Guinea.
Important Animals: Ceratodus (Australian Lungfish), Sphenodon, Casuarius, Emu, Kiwi, Duck billed platypus, Spiny anteater, Opposum, Kangaroo, Marsupial cat.”(iv) Ethiopian Realm
“It includes Africa, Arabia and Madagascar.
Important Animals: Protopterus (African Lungfish), Rhacophorus, Crocodile, Chamaeleon, Python, Ostrich, Scaly-anteater, Chimpanzee, Gorilla, Zebra, Elephants, Hippopotamus, Rhinoceros, Giraffe, Lion, Tiger.”(v) Nearctic Realm
“It covers Canada, United States of America and Mexico.
Important Animals: Sucker fish, Tiger salamander, Amphiuma, Heloderma (Poisonous Lizard), Alligator, Hawk, Opossum, Porcupine.”(vi) Neotropical Realm
“It includes the area of Central and South America and Island of West-Indies.
Important Animals: Lepidosiren (South American Lung fish), Caecilians (Apoda), Hyla, Pipa, Rattle snake, Rhea, Opossum, Vampire bat, Llama (Like Camel), Marsupial rat.”“Oriental realm is separated from Palaearctic realm by Himalayan Mountains. Ethiopian realm and Australian realm are separated by sea. Oriental realm and Australian realm are separated by Wallace’s line. Palaearctic realm and Nearctic realm together form Holoarctic region.”
Discontinuous Distribution of Closely Related Species
“Sometimes closely similar species exit at widely separated places without any representative, in intervening territory. This is called discontinuous distribution. Two specific examples of discontinuous distribution are given below.”
(a) Lung Fishes
“During early stages of continental drift, South America, Africa, Antarctica and Australia were interconnected. Later on they were separated. Antarctica was shifted to a far away place. Now the lung fishes are only found in South America, Africa and Australia as shown in the Map No. 5.4”
(b) Alligators
“They occur only in south-eastern United States and eastern China. The North American continent was connected with East Asia in early coenozoic. The alligators were distributed over the entire region. But due to certain barriers, the alligators of two regions were separated for long time and developed some mutations. Therefore, these alligators are somewhat different but they are related species of the same genus.”
“If we look at a map of the world on a sheet of paper, cut out the outlines of South America and Africa and bring them together (Map No. 5.5). We find that the right side of South America fits into the left side of Africa.”
Source Citation
Researcher: Pratima Kumari, S
Thesis Title: Copper toxicity on fry of fresh water edible fish pangasianodon hypophthalmus
Supervisor: Prabhakara Rao, Y
University: Andhra University
Year of Completion: 2012
Exit Page Number: 183
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