1. Do Now Activity
What is the difference between a homologous and vestigial structure?
A long time ago, there were scientists that probably observed giraffes with really short necks. We do not see these giraffes with short necks anymore. What could have happened during the evolution of the giraffe?
True/False: An example of evolution is when chameleons change their color to blend into their environments.
If #3 was False, re-write the sentence to make it a true statement.

2. Section 5-3: Natural Selection
Essential Question:
How does competition for limited resources lead to an adaptation within a species?
Learning Target
Explain the four factors that result in evolution of a species
Explain the relationship between the factors of evolution and the adaptation of a species that results from competition for limited resources.
Section 5-3: Natural Selection

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4. Don’t forget to chunk your notes!

5. all species, living and extinct, came from the same original species.
overview
Common Ancestor
all species, living and extinct, came from the same original species.

6. overview
Each living species has descended, with changes, from other species over time.

7. A single “tree of life” for all living things on Earth.
overview
A single “tree of life” for all living things on Earth.

8. Don’t forget to chunk your notes!

9. Individuals have different traits.
Natural selection
Individuals have different traits.

10. Traits can be passed on to offspring.
Natural selection
Individuals have different traits.
Traits can be passed on to offspring.

11. More offspring are made then can survive to reproduce.
Natural selection
Individuals have different traits.
Traits can be passed on to offspring.
More offspring are made then can survive to reproduce.

12. high birth rates + limited resources = competition
Natural selection
high birth rates + limited resources = competition

13. Organisms struggle to exist when there is _____ for resources.
Natural selection
competition
Organisms struggle to exist when there is _____ for resources.
competition

14. Don’t forget to chunk your notes!

15. Factors that cause evolution
1. Carrying Capacity: species growth limited by the environment
The potential for a species to increase in number

16. Factors that cause evolution
1. Carrying Capacity: species growth limited by the environment
The potential for a species to increase in number

17. Factors that cause evolution
1. Carrying Capacity: species growth limited by the environment
The potential for a species to increase in number

18. Factors that cause evolution
1. Carrying Capacity: species growth limited by the environment
The potential for a species to increase in number

19. Factors that cause evolution
1. Carrying Capacity: species growth limited by the environment
The potential for a species to increase in number

20. Factors that cause evolution
2. Variation: differences
The heritable genetic variation of individuals in a species due to mutation and sexual reproduction

21. Factors that cause evolution
3. Competition: limited resources
Competition for limited resources

22. Factors that cause evolution
4. Fitness: survive and reproduce
Adaptations: traits that increase survival
Proliferation of those organisms that are able to better able to survive and reproduce in the environment

23. Don’t forget to chunk your notes!

24. “Survival of the Fittest”
Darwin called this Natural Selection.
Best fit to the environment can survive and reproduce.
Over time natural selection changes genes in population.
New species = Evolution

25. “Survival of the Fittest”
Variations  Adaptations  Fitness
Natural Selection/Survival of the Fittest
A Very Long Time  EVOLUTION!

26. Do now activity Give an example of homologous structures.
Give an example of vestigial structures.
True/False: The 5 forms of evolutionary evidence are: embryo development, fossil record, competition, DNA, & variation.
If #3 was False, re-write the sentence to make it a true statement.