Macroevolutio1 - mya A second extinction occurred in the...

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Macroevolution A Brief History of Life Geological and paleontological evidence has allowed us to piece together a picture of how life on earth evolved from the earliest single-celled organisms to the diversity of single- and multi-celled organisms that have lived through history. Figure%: History of Life on Earth Mass Extinctions The history of life on earth is punctuated by a series of mass extinctions, during which the number of species on earth plummeted. Each of these extinctions changed the landscape of global diversity and allowed new types of organisms to thrive in the aftermath.
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The first mass extinction occurred in the Ordovician period, about 500 million years ago (500
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Unformatted text preview: mya). A second extinction occurred in the late Devonian period, about 360 mya. This extinction paved the way for a diversification of land plants, insects, and amphibians in the Carboniferous period. The next mass extinction took place at the end of the Paleozoic era in the Permian period, about 250 mya. After this extinction, marine and reptile diversity increased greatly, eventually leading to the "Age of the Dinosaurs." The dinosaur age crashed to a halt in the late Cretaceous period (70 mya), when the most recent mass extinction eliminated the last dinosaurs and allowed mammals to become a dominant form of life....
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This note was uploaded on 01/27/2012 for the course BIOLOGY BSC1005 taught by Professor Rodriguez during the Winter '09 term at Broward College.

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Macroevolutio1 - mya A second extinction occurred in the...

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