Fossils

Question 1

What can well-preserved fossils provide? (2)

Answer 1

1. A record of organisms that lived a long time ago

2. Evidence that animals and plants can change over long periods of time

Question 2

Which organism, unlike some others, has a well completed fossil record?

Answer 2

A horse

Question 3

What can fossils be formed from?

Answer 3

Bones and shells (don’t decay easily)- hard
dead plants and animals in resin
Foot prints or burrows that are covered in sediment

Question 4

What is the Gradual Replacement of Minerals? (3 steps)

Answer 4

1. Hard body parts last a long time when buried
2. Eventually replaced by minerals- rock-like substance in same shape
3. Surrounding sediments also turn to rock- fossil stays distinct

Question 5

How does the findings of fossils support the theory of evolution?

Answer 5

Simplest organisms are found in the oldest rock, while more complicated organisms are found in the newest rock

Question 6

Fossils of the ……. organisms are found in the …….. rocks, and fossils of more ……… organisms in the ……… rocks. This supports the theory of …….

Answer 6

Fossils of the simplest organisms are found in the oldest rocks, and fossils of more complex organisms in the newest rocks. This supports the theory of evolution

Question 7

What can scientists learn from studying fossils?

Answer 7

How much, or how little, organisms have changed as life has developed on earth

Question 8

Are fossil records more often complete or incomplete?

Answer 8

Incomplete

Question 9

Why is it difficult to know from fossil records what many early organisms looked like?

Answer 9

Many of them were sift bodied, so left few traces behind

Question 10

How long did it take for a modern horse to evolve?

Answer 10

60 mil years

Question 11

What were the main changes as the horse evolved?

Answer 11

1. Grew in height
2. Multi-toed foot into hoof (jungle to plains)
3. Teeth grew and outer layer became more complex (chewing grass)