6.1 Origins of life on earth Flashcards
1
Q
How old is the Earth?
A
4500 million years
2
Q
When did life begin on earth?
A
3500 million years ago
3
Q
How did life originate on earth?
A
Debate whether started on earth on came from other planets (comets ect)
4
Q
How do we date fossils?
A
By dating the rocks they are found in
5
Q
How are fossils formed? 4
A
From the hard parts of animals that do not decay easily
From parts of organisms that have not decayed because some of the conditions for decay are absent
When parts of the organism are replaced by other materials such as minerals when they decay
As preserved traces of organisms, eg footprints.
6
Q
Why are some fossils destroyed over time?
A
Because of geological activity, eg earthquakes, errosion
