Evidence for evolution

Question 1

Fossil record:

Answer 1

• Simple to complex organisms
• More and more like modern life – Extinct life forms closer to now are more similar then those of 100 million years ago.
• Pattern of changed leads directly to the modern types of life on Earth

Question 2

Transitional fossils shows?

Answer 2

reveals the remains of ‘intermediate stages’ of life. These are fossils of organisms that are ‘in between’ in the evolution of a new type from a previously existing type of life.
• Gives us a glimpse of the changes from one type to another as evolution progressed

Question 3

Example of transitional fossils (1):

Answer 3

Archaeopteryx (dinosaur – bird) – most common transitional fossil. Dates from 150 mya. Bones are those of small dinosaur but covered with feathers.

Question 4

Example of Transitional fossils (2):

Answer 4

Cooksonia – Plant seems part seaweed ad part moss. First plants to live on dry land maybe.

Question 5

Selective Breeding:

Answer 5

• Changes occurring from one generation to another, as certain features are ‘selected’ in favour of others.

Question 6

How did we contribute to selective breeding?

Answer 6

• Domesticated plants and animals – Humans chose of eg. Which bull to breed with the cows or which seed to keep for next year’s crop drastically change all these plants and animals
• Modern wheat nothing like wild grass we bred from
• Cabbages and cauliflowers used to be the same thing, but have changed by selective breeding

Question 7

Comparative anatomy:

Answer 7

• Many living organisms gave basic structures which show that they have evolved from common ancestor

Question 8

Example of Comparative anatomy:

Answer 8

The Pentadactyl Limb, fish, amphibians, reptiles, mammals and birds have same basic bone structure in their limbs. Same bone structure as evolved from an original ancestor which had that structure?

Question 9

Cell Chemistry

Answer 9

• Structure of DNA, cell proteins and chemical pathways all point to a common ancestry

Question 10

Cell Chemistry (Genetic Code)

Answer 10

Human DNA is 99% identical to that of a chimapzee, but much less like that of a horse, lizard etc. Yet all these organisms use exactly the same ‘genetic code’ in the DNA itself. Evolution from common ancestor

Question 11

Cell Chemistry ( Cell Chemicals and Pathways)

Answer 11

Chemicals in living cells which control cell chemistry show the same patterns as DNA