B15.5 Evidence for evolution

Question 1

What are fossils?

Answer 1

Remans of organisms from millions of years ago that are found in preserved places

Question 2

How does lack of decay occur and what is it?

Answer 2

When an animal or plant does not decay after it has died - may occur if there is little oxygen or a poisonous gas has killed of bacteria - or the temperature is too low
These are very rare - can extract the DNA and identify features such as diet and colour

Question 3

How does mineralization occur?

Answer 3

The reptile dies and falls to the ground
Flesh rots leaving the skeleton and some soft tissue
Sand or other minerals cover the soft issue in sediments and undergoes mineralization
Gradually skeleton is discovered due it being visible above the ground - Mineralisation most common

Question 4

What is preserved traces?

Answer 4

None of the original organism is left behind but are traces left behind - such as footprints

Question 5

Why is the fossil record incomplete?

Answer 5

Many fossils that are still to be found
Right conditions were rare - so many organisms did not become fossilised
Many of the earliest forms of life were soft-bodied organism - which means they left very little trace

Question 6

Why fossils are such important evidence for the way life has developed?

Answer 6

Demonstrate how plants and animals have changed over time, how different organisms have developed, and that some no longer exist