Chapter 19
The History of Life
Life in the Cambrian
The Origins of Life Initiative |
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The Science of Biology |
Think about it - Fossils are priceless treasures. They tell of life-and-death struggles and of mysterious worlds lost in the mists of time. Taken together, the fossils fof ancient organisms make up the history of life on Earth called the fossil record. How can fossils help us understand life's history?
Key Questions Include:
What do fossils reveal about ancient life?
How do we date events in life's history
How was the geologic time scale established?
How have our planet's environment and living things shaped the history of life on Earth?
What processes influence whether species and clades survive or become extinct?
How fast does evolution take place?
What are two patterns of macroevolution?
What characteristics are typical of coevolving species?
What do scientists hypothesize about the origin of life on Earth?
What theory explains the origins of eukaryotic cells?
What is the evolutionary significance of sexual reproduction?Active Art: Fossil Formation
SciLinks: Extinction
Murder in the Permian
Just over 250 million years ago, during the Permian period, life on Earth came as close as it ever has to being wiped out. As you read about this mystery, look for clues as to what could have killed so many different forms of life. Then, solve the mystery.
