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Preindustrial man influenced and changed the earth's ecosystems decisively. The disappearance of large animals from all continents (Eurasia, e.g., mammoth; America, e.g., the giant sloths and the giant armadillo) after the Pleistocene was most probably due to a large extent to the early hunters and collectors. Corn-growing and breeding of domestic animals led to the disappearance of their wild forms (e.g., the wild form of today's old world camel is unknown) and the cultivation of huge monocultures. The increasing need for wood resulted in the disappearance of forests almost all over Europe. Specific needs, such as pig-raising or bee-keeping, supported the formation of particular landscapes, e.g., sparsely wooded forests and extensive heathlands. All these factors resulted in extreme soil erosion and the disappearance of nutritionally important minerals from the soil, which was thus severely depleted.  相似文献   
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Africa has lost only very few big mammals at the end of the pleistocene. Evidence is put forward that the reason for the present richness of the African mammal fauna is a very early coevolution between evolving man and the megafauna of this area. Areas without such an early coevolution suffered severe losses (up to 100%) of their native megafauna, when early hunters invaded them.  相似文献   
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