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What can fossils tell us about the history of life on Earth?🌏
Fossils are the preserved traces or remains of organisms that live thousands or millions of years ago.
- We find fossils when the rocks containing them are weathered
- The history of life on earth as shown by the fossils from different periods of time are known as fossil record
- This suggests that organisms have changed gradually through time (process called evolution)
- Soft tissue and decay do not usual form fossils, so soft-bodied organisms leave littlel fossil evidence behind
- Other dead organisms did not form fossils because the hard parts were destroyed
- Many fossils are buried deep in the earth and have no yet been found
- These gaps mean that scientists must interpret how organisms changed over time from incomplete data
- The same sets of fossil data can be interpreted in different ways, often because fossils are frequently damaged or incomplete
- The more fossil evidence we can collect, the better conclusions we can draw
- We can date fossils accurately now and use computers to model how the organism might have looked
![broken image](http://custom-images.strikinglycdn.com/res/hrscywv4p/image/upload/c_limit,fl_lossy,h_9000,w_1200,f_auto,q_auto/4936730/285552_866329.jpeg)
More evidence for evolution🦍
This may be asked in I/GCSE Biology
- Most vertebrates have limbs, and though the limbs may look very different on the outside, the internal bones structure is similar. This is also true of fossil vertebrates
- Even fossil ancestors of limbless living vertebrates have the same basic five fingered (pentadactyl) limb structure
- This suggests that all vertebrates evolve from one common ancestor hundreds of millions of years ago
- Looking at the fossil record, scientists can explain the evolution of different forms of pentadactyl limb in different vertebrate species as adaptations to different ways of living and moving.
![broken image](http://custom-images.strikinglycdn.com/res/hrscywv4p/image/upload/c_limit,fl_lossy,h_9000,w_1200,f_auto,q_auto/4936730/965232_746729.png)
Drafted by Catrina (Biology)