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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
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.
Drafted by Catrina (Biology)