1. Chapter 16
Darwin

2. Evolution Game
Play the game “Who wants to live a million years” on Miss D’s wikispace
If you finish before time is called, click around on the other links (Quiz, Natural Selection, or Darwin’s Bio)

3. With your partner… Was the game easy or hard? Explain.
Was there a trick to the game? Explain.
What mechanism of evolution is this game explaining?
What types of forces cause evolution to occur?

4. Darwin’s Theory of Evolution
Darwin is the father of evolution
Evolution = the process of change over time, descent from common ancestors
Evidence:
1. Species vary globally
2. Species vary locally
3. Species vary over time

5. Why study tropical areas?

6. Species vary Globally
Rheas = flightless birds that look and act a lot like ostriches, yet rheas lived in South America
Ostriches lived in Africa
Emu lived in Australia
Darwin noticed that different, yet ecologically similar, animal species inhabited separate, but ecologically similar, habitats around the globe.

7. Species vary locally Two species of Rhea’s living in South America
Species = population that can breed and produce fertile offspring
Different shell shapes in tortoises of Galapagos
Darwin noticed that different, yet related, animal species often occupied different habitats within a local area

8. Species vary over time
Darwin collected fossils (preserved remains of animals)
Some fossils of extinct animals were similar to living species.

9. Ideas that Shaped Darwin’s Thinking
Hutton and Lydell proved that Earth is extremely old and that the processes that changed Earth in the past are the same processes that operate in the present.
Examples?
Darwin - If Earth changed over time, could life too?

10. Lamarck’s Evolutionary Hypthesis
Read p. 456 with a partner and explain why Lamarck’s ideas were not correct

11. Malthus’s view
If human population grew unchecked, there would not be enough living space and food for everyone.

12. Artificial Selection
Artificial selection: the selective breeding of domesticated plants and animals
Shows convincing evidence that humans were playing the role of the environment in nature

13. Natural Selection Natural selection the basic mechanism of evolution
1. Struggle for existence
2. Variation and adaptation
3. Survival of the fittest (fitness = survival and reproduction)

14. Struggle for Existence
Members of a population must compete for food, living space, etc.

15. Variation and Adaptation
Some variants are better suited than others
Faster, longer claws, camouflage, sharper teeth
Adaptation = heritable characteristic that increases organisms ability to survive and reproduce
Bowerbird display

16. Survival of the Fittest
Differences in adaptation affect fitness (how well an organism can survive and reproduce
Different in rates of survival and reproduction= survival of the fittest

17. Natural selection
Process by which organisms with variations most suited to their local environment survive and leave offspring
Similar to artificial, but nature is controlling
When does it occur?
More individual are born than can survive (struggle for existence)
Natural heritable change (variation and adaptation)
Variable fitness among individuals (survival of the fittest)

18. Natural Selection Myths
Does not make organisms better
But does enable them to pass on their genes
Does not move in a fixed direction
No one perfect way of doing something, ex pollination
Not the only mechanism that drives evolution

19. Common descent
According to the principal of common descent, all species – living and extinct – are descended from ancient common ancestors
Evidence?

20. Evidence of Evolution Biogeography (distribution)
The Age of Earth and Fossils
Comparing Anatomy and Embryology (homologous, analogous and vestigial structures)
Genetics and Molecular Biology (amino acid sequences)
Lab – Evidence of Evolution