B2 6 Old and New Species

Question 1

What are fossils?

Answer 1

Fossils are the remains of organisms from many years ago that are found in rocks

Question 2

What information do fossils give us?

Answer 2

Fossils give us information about organisms that lived millions of years ago. Eg: dinosaurs

Question 3

How do fossils form?

Answer 3

• From hard parts of an animal. These are the bits that don’t decay easily. Eg: bones, teeth, claws or shells • When an animal or plant does not decay easily. This happens if one or more of the conditions needed for decay are not present Examples: little or no oxygen, poisonous gases kill off bacteria, low temp • When harder parts of the animal or plant are replaced by other minerals. Most common type of fossils • Traces left behind by animals. Eg: fossil footprints, burrows, rootlet traces and droppings •

Question 4

Ice fossils:

Answer 4

• Rare • Gives clear insight into what an animal looked like • Tell us what an animal had been eating • DNA can also be extracted and compared to modern organisms

Question 5

Why is the fossil record not complete?

Answer 5

• Many of the earliest life forms were soft-bodied organisms = little fossil trace left behind • = little valid evidence of how life began • Most organisms that died did not become fossilised. The right conditions for fossil formations were rare • Fossils also destroyed by geological activity • Rock broken down, worn away, buried and melted over years • Fossils yet to be found

Question 6

Formation of fossils:

Answer 6

Question 7

Fossil tracks formation:

Answer 7

Question 8

What do fossils show us?

Answer 8

Fossils show us how much or how little organisms have changed as life has developed on earth