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PAST LIFE
Lesson 1 - Page 7

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Fossils are clues to the type of organisms that roamed or swam on the Earth. However, fossils provide us with more information. They can tell us about the paleoecology or the relationship between organisms and their environments, if we can decipher the clues. Paleontologists want to determine the physical, chemical and biological interactions that can limit the distribution and abundance of different species. They are always searching as to why an organism may have gone extinct. Today we know that when an organismís environment changes or when other organisms invade another habit, extinction can occur.

Fossils also indicate that organisms have changed through time. As we learn which fossils lived in what time, we can retrace how the environment looked and assign periods of time to each fossil group. Horseshoe crabs for instance have not changed since they were first recorded in the fossil record. Foraminifera a protist, changes shapes through time and help geologist age date rocks. 


Horseshoe crab


Foraminifera change
through time

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