History of Zoogeography [Autosaved].pptx

History of zoogeography
In this lecture I will discuss the role of different scientist in zoogeography.

1. History of Zoogeography Prof. Asif Saleem

2. Zoogeography & Scientists: Zoogeography is a branch of Biogeography that deals with the study of past and present distribution of animals on Earth. Over the centuries, this science has evolved due to the contribution of many scientists, some notable efforts are discussed here:

3. First Attempt at the Biogeographic Division of Earth Ludwig K. Schmarda (1885) divided all animal life, marine and terrestrial, in a single zoogeographic scheme. He divided the world into 21 land and 10 marine realms. "A zoogeographical region/realm is a sub-division of the Earth having a unique fauna, i.e. species that are found only in that area.”

4. Contributions of Philip Lutley Sclater It was Philip Lutley Sclater who divided the terrestrial world into the biogeographic regions that, essentially, are still in use today. This was done in 1858 in a small paper entitled On the General Geographical Distribution of the Members of the Class Aves. His scheme was based only on the distributional patterns of birds. Sclater’s work proved to be useful for almost all groups of terrestrial animals.

5. Contributions of Philip Lutley Sclater He divided the surface of the earth into six regions:  Palearctic Region (Europe)  Ethiopian Region (Africa)  Indian Region (South Asia)  Australian Region (Australia, Tasmania & New Guinea)  Neotropical (South America)  Nearctic (North America)

6. Contributions of Philip Lutley Sclater According to him: Paleogaea / Old World (eastern half of the world’s zoogeographical regions). Neogaea / New World (western half of the world’s zoogeographical regions). Palearctic Ethiopian Indian Australian Paleogaea Nearctic Neotropical Neogaea

7. Contributions of Philip Lutley Sclater

8. Contributions of Thomas Henry In 1868, Thomas Henry Huxley proposed the division of the surface of Earth into two primary regions called Arctogaea (northern region) and Notogaea (southern region). Arctogaea is comprised of Palearctic, Nearctic, Ethiopian, and Indian regions. Notogaea is comprised of Neotropical and Australian regions. His scheme was regarded as invalid and later on discarded .

9. Contributions of Thomas Henry

10. Natural Selection & Zoogeography (DARWIN & WALLACE) When Charles Darwin visited the Galapagos Islands in 1835 , he was struck by the distinctiveness, yet basic similarity , of the fauna to that of mainland South America. 20 years later, When Alfred Russel Wallace traveled through the Indo-Australian region , “He was puzzled by the contrasting character of the island faunas, some with Australian relationships and others with southeast Asian affinities.” The key for both Darwin and Wallace was the realization that distributional patterns had evolutionary significance.

11. Natural Selection & Zoogeography (DARWIN & WALLACE) The announcement of their joint theory by Darwin and Wallace in 1858 in the Journal of the Linnean Society of London and, especially, the publication of Darwin's Origin of Species in 1859. Darwin noted that the interhemispheric migratory movement from north to south, suggested that this was due to the natural selection and competition to a higher stage of dominating power.

12. The Geographic Distribution of Animals by Alfred Russel Wallace While Darwin went on to investigate many other aspects of evolutionary change , Alfred Russel Wallace applied himself primarily to zoogeography. Finally, in 1876, Wallace published his work in which conclude following points: 1. Paleoclimatic studies are very important for analyzing extant distribution patterns. 2. Competition, predation , and other biotic factors play important roles in the distribution, dispersal, and extinction of animals. 3. The common presence of organisms not adapted for long-distance dispersal is good evidence of past land connections.

13. The Geographic Distribution of Animals by Alfred Russel Wallace 4. Islands may be classified into three major categories i.e. 5. Studies of island biotas are important because the relationships among distribution, speciation, and adaptation are easier to observe. Continental islands recently set off from the mainland Continental islands long separated from the mainland Oceanic islands of volcanic origin

14. Wallace’s Division of Zoogeograhical Realms/ Regions The six zoogeographical regions and their sub-regions (four each) given by Wallace are as follows: 1. Palearctic Region – Sub-regions: European, Mediterranean, Siberian and Manchurian. 2. Ethiopian Region – Sub-regions: East Africa, West Africa, South Africa, and Malagasy. 3. Oriental Region – Sub-regions: Indian, Ceylonese, Indo-Chinese, and IndoMalayan. 4. Australian Region – Sub-regions: Austro-Malayan, Australian, Polynesian, and New Zealand. 5. Neotropical Region – Sub-regions: Chilean, Brazilian, Mexican, and Antillean. 6. Nearctic Region – Sub-regions: Californian, Rocky Mountains, Alleghany, and Canadian.