1. B1 Chapter 7 Evolution The Final Chapter! Title for today: Theories of Evolution You need: Notes on Lamarck’s Theory and Darwin’s theory.

2. Theories of Evolution Learning Objectives: To understand what is meant by the ‘theory of evolution’ to explain why fossils are important To have an awareness of how old the Earth is

3. What is a theory? A scientific theory is an explanation of the natural world that has been repeatedly confirmed through observation and experiment

4. What is the theory of evolution? The theory of evolution states that: All species of living things that exist today (and many more which are now extinct) have evolved from simple life forms, which first developed more than 3 billion years ago. How old is the Earth? The Earth is 4.5 billion years old

5. How do we know evolution happened? http://www.youtube.com/watch?v=ewtw_nZ UIDQ http://www.youtube.com/watch?v=ewtw_nZ UIDQ

6. Fossils as evidence What are fossils? How can they provide evidence for evolution? Why do not provide complete evidence for this theory?

8. What drives this change?

9. A fast runner on hard ground It has one toe forming a hoof Looks more like the modern horse with one hoof Slightly bigger Walks mainly on one toe Has 3 toes on the ground To run faster on drier ground Small Lives on swampy land Toes are well spread

10. How did the giraffe get such a long neck?

11. Lamarck’s Theory of Evolution He believed that all creatures were linked by a ‘fountain of life’ And animals inherited acquired characteristics The characteristics that help that organism to survive are passed to their offspring So if your parents are body builders then you are born that way

13. Why was Lamarck’s theory wrong? It cannot account for all the observations on Earth His theory implies that all organisms would gradually become complex Simple organisms would disappear (this is not the case)

14. Darwin’s Theory of Evolution Darwin set out in 1831 on a voyage on HMS Beagle At the Galapagos islands he saw different features on a variety of finches

16. Darwin’s Theory of Evolution All living organisms have evolved from simpler forms Evolution has come about by a process called natural selection Only those most adapted to their environment will survive, reproduce and pass on their genes. Survival of the fittest

17. Darwin did not publish his theory for many years. Why reasons could there have been for this?

18. Can you explain what this diagram represents? How did it happen?

21. Evolutionary Trees

24. 1.Why is Homo floreiensis not connected to any other species? 2.From which common ancestor did homo sapiens and homo erectus evolve? 3.Lines linking Homo ergaster and homo habillis join around how many years ago? What does this represent? 4.Who was the closest ancestor of Australopithecus africanus?