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Unformatted text preview: Ch. 24 History and Biogeography Biogeography Defined as the study of the spatial distribution of organisms, both present and past Alfred Wallace described six biogeographic regions of animal distributions o Each has distinctive uniformity in taxonomic units Neartic and Paleartic o In boreal, some of the same species o Share many genera and families o Neartic has more reptiles and families of vertebrates Ethiopian o Most varied vertebrate fauna Neotropical o Most distinctive and varied fauna o Few ungulate species Oriental o Rich in primate species o Lacks a variety of families Australian o Dominance of marsupials o Low number of other vertebrates History of Biodiversity • Use fossil records to estimate biodiversity • Geologic time scale divided into eras: o Based on major changes in flora and fauna o Smaller divisions also based on biotic changes Referred to as periods • Paleozoic – old animals o Invertebrates appeared in fossil record 5.9 million years ago o Starfish, arthropods, mollusks o Other groups that arose during Paleozoic: Fish Terrestrial plants Amphibians Reptiles •...
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- Fall '10
- Ecology, mass extinction, anthropogenic extinction, extinction Extinction