1. Evolution
Biology

2. Evolution is change over time
THEORY: best explanation science has to offer about where different organisms came from
This theory changes as new scientific information becomes available

3. Charles Darwin Father of modern evolution theory
Formed his theory after traveling around the world on the Beagle

4. Important stop: Galapagos Islands
Collected various plants and animals
Observed behaviors
Drew sketches
Finches (type of bird)
13 species of finches
Many are born but do not survive
Found on different islands
Beak size and shape varied
Ate different food
Important stop: Galapagos Islands

5. Darwin’s observations:
1. Variation: differences between members of the same species
Variation is important to survival!
Variety in a species makes it easier to survive especially when change occurs

6. What causes variation?
Random Mutations
Beneficial
Harmful
Silent

7. Darwin’s Observations
2. Overproduction of Offspring
When organisms reproduce they have more offspring then can actually survive

8. Darwin’s Observations
3. Competition
This leads to competition
(Survival of the Fittest)

9. Darwin’s Observations
4. Natural Selection
Organisms with traits well suited to the environment survive and reproduce at a greater rate
You have the genes to be successful in your environment or you don’t
Over time, population will be more like those that reproduce

10. An adaptation is a beneficial mutation that makes it possible for an organism to live in a particular place and in a particular way and reproduce.
Physical (like the size, shape or color)
Physiological- the way in which its body works
Behavioral- how the organism acts

11. Name 3 adaptations for each organism shown
Name 3 adaptations for each organism shown. Think about where they live, what they eat, what eats them…

18. Natural Selection: An Example
In the U.S., people have used shampoos with particular chemicals in order to kill lice
We have a lot of lice that are resistant to the chemicals in those shampoos.
(Resistant means unaffected)

19. Hypothesis A:
Exposure to lice shampoo caused mutations in the lice. Some lice became resistance to the shampoo.

20. Hypothesis B:
When the lice were exposed to the shampoo, the non-resistant lice died a sudsy death. The lice who were able to survive the shampoo survived and reproduced. They did not mutate.

21. Which of these hypotheses is correct?
Hypothesis B
Why?
Variation is there already
Shampoo killed the less fit (non-resistant) lice
More fit (resistant) lice live and reproduce to make more fit (resistant) lice

22. MUTATION ARE NOT CAUSED!

23. DARWIN
Darwin called these mutations or changes ADAPTATIONS