Choose from these words to fill the blanks below:

genera, rodents, disasters, genetic, Chile, swamps, cusp, game, 200, jungles, 100, islands, lemurs, Siberia, pampas, influential, forests, disconnected, ocean, victims, reindeer, similar, American

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the first globally                       influential event that humans achieved was cause the ecological catastrophe in Australia 50,000 to 40,000 years ago

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the second globally influential event was a similar ecological catastrophe on the                 American continents

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humans arrived about 14,000 BC

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arrived on foot while sea levels were low enough that a land bridge connected north Eastern Siberia with northwestern Alaska

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they were probably in pursuit of large         game animals such as mammoths and                 reindeer which migrated back and forth along this land bridge

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they then spread down into the continent of America

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having been adjusted to living in the cold and long winters of               Siberia, within 2,000 years they adjusted to a variety of habitats and ecosystems:

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thick               forests of Eastern United States

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            swamps of the Mississippi Delta

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deserts of Mexico

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steaming               jungles of central America

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open             pampas of Argentina

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by 10,000 BC, humans already inhabited the most southern point of           Chile

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no other animal had ever moved into such a variety of radically different habitats without undergoing any significant               genetic mutation.

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you can find some animals which live in various habitats like this, for instance ants, but evolution throughout the ages has given them specific features which help them to survive in each of these environments, for instance, ants in the delta of the Mississippi are structurally different than ants in the pampas of Argentina, it took millions of years for them to adapt to these different places. Sapiens adapted well in less than 2,000 years.

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the human migration from Siberia to Chile left behind a long trail of               victims

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American animals 60,000 years ago were much more varied than today

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60,000 there were mammoths and mastodons (difference: mastodons had         cusp-shaped teeth different from mammoth and elephant teeth)

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              rodents and beavers the size of bears

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saber-tooth cats

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giant sloths

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within a few thousand years of humans arriving in North America, 34 of 47 genera of large mammals disappeared, South America lost 50 out of 60 genera large mammals, and we are talking about             genera not species, each genera contained many species and they all disappeared

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many smaller species also died out

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this was one of the biggest and swiftest ecological                   disasters to ever befall the animal kingdom

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the more               similar you were to Homo sapiens, the less chance you had of surviving

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at the time of the cognitive revolution (70,000 year ago), earth was home to approximately       200 genera of large terrestrial mammals (weighing over 50 kilograms), by the time of the agricultural revolution (12,000 years ago), there were only       100 genera of large terrestrial mammals left, this means that Homo sapiens drove to extinction about half of the worlds large mammals long before we invented the wheel or writing, or iron tools.

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after agricultural revolution

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the extinctions did not stop after the agricultural revolutions, told by the archeological record of many               islands

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there were no new continents to conquer, but there were islands, and archeological records show that almost every time humans arrived on an island, large animals on that island would go extinct

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Madagascar

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                        disconnected from Africa

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for millions of years evolutionary processes produced a very unique collection of animals

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largest bird, flightless, 3 meters tall

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            lemurs, larger than gorillas

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humans never really lived in harmony with nature

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the large animals of the           ocean suffered relatively little from the ancient extinctions

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in an analogy of the Biblical flood, the real flood was not water but humans who migrated around the global and decimated many kinds of animals, the only animals it protected were the ones it domesticated for its purposes such as horse, cows, sheep, and pigs