1. NOTES WILL COVER:
Evolution
Mutations
Natural Selection
Genetic Variations
Adaptations
Selective Breeding

2. Unit 2 :Chapter 10 : Section 3
Evolution
Many scientists believe that changes in the plants and animal species on earth can be explained by evolution.
Unit 2 :Chapter 10 : Section 3

3. Theory of Evolution
The theory of evolution is the process by which populations accumulate inherited changes over time.

4. Mutations and Natural Selection
According to the theory of evolution, two processes are necessary for populations to change over time. These are mutations and natural selection.
Unit 2 :Chapter 10 : Section 3

5. Unit 2 :Chapter 10 : Section 3
Mutations
In order for a population to change, genes must be able to change
Genes are made of DNA
DNA is made of 4 parts, called nucleotides
Unit 2 :Chapter 10 : Section 3

6. Unit 2 :Chapter 10 : Section 3
Mutations
The order of the nucleotides that are put together determines what characteristics you will receive from your parents.
Unit 2 :Chapter 10 : Section 3

7. Unit 2 :Chapter 10 : Section 3
Mutations
Changes in the type or order in which these bases appear are known as mutations.
Mutations can be harmful, helpful, or not change an individual at all
Unit 2 :Chapter 10 : Section 3

8. Unit 2 :Chapter 10 : Section 3
Natural Selection
Natural selection is a word that Charles Darwin made very popular.
Unit 2 :Chapter 10 : Section 3

9. Unit 2 :Chapter 10 : Section 3
Natural Selection
According to Darwin’s theory, natural selection says that:
“organisms that are better able to survive and reproduce in an environment are more likely to pass their traits on to future generations”
Unit 2 :Chapter 10 : Section 3

10. 4 Steps of Natural Selection
Overproduction
Genetic Variation
Struggle to Survive
Successful Reproduction
Unit 2 :Chapter 10 : Section 3

11. Natural Selection: Overproduction
More individuals are born than will become adults
Not all of these baby rats will become adults
Unit 2 :Chapter 10 : Section 3

12. Natural Selection: Genetic Variation
The individuals in a population are NOT exactly the same
Each has its own set of traits, such as size, color, and the ability to find food
Unit 2 :Chapter 10 : Section 3

13. Natural Selection: Genetic Variation
Some traits make an individual more likely to survive and reproduce
Other traits make survival and reproduction less likely
Unit 2 :Chapter 10 : Section 3

14. Natural Selection: Struggle to Survive
An environment might not be able to support all of the individuals born
Also, many individuals are killed by other organisms
Only some of the individuals in a population become adults and reproduce
Unit 2 :Chapter 10 : Section 3

15. Natural Selection: Successful Reproduction
The organisms that survive and reproduce have traits that are carried on by their many offspring
This makes the “good” traits more dominant in the populations of individuals
Unit 2 :Chapter 10 : Section 3

16. Unit 2 :Chapter 10 : Section 3
Practice
How are the feathers of peacocks and the bright flowers of some plants related to successful reproduction?
The feathers of peacocks attract mates. The bright coloring of some flowers attracts pollinators. Both of these traits increase the chances of successful reproduction.
Unit 2 :Chapter 10 : Section 3

17. Unit 2 : Chapter 14 : Section 2
Animals and Behavior
Innate behavior- a behavior that is influenced by genes and does not depend on learning or experience
Learned behavior- a behavior that has been learned from experience or observation
Migrate- to travel from one place to another
Hibernation- a period of inactivity and lowered body temperature that some animals experience in the winter
Estivation- a period of reduced activity that some animals experience in the summer
Unit 2 : Chapter 14 : Section 2

18. Unit 2 : Chapter 14 : Section 2
ADAPTATIONS
There are some traits among species that help to enhance the survival of those species
Animals use many different methods to get food. Chimpanzees use sticks to get ants out of an anthill. This way they can get enough food while using the least amount of energy.
Unit 2 : Chapter 14 : Section 2

19. Unit 2 : Chapter 14 : Section 2
ADAPTATIONS
Some animals use camouflage to blend into the environment
Some animals can drive other animals away by using external stimuli. Skunks use chemicals as external stimuli.
Unit 2 : Chapter 14 : Section 2

20. Unit 2 : Chapter 14 : Section 2
ADAPTATIONS
Many animals are brightly colored and use this external stimulus as warning coloration
Often bright colored organisms are poisonous, and predators stay away from them
Unit 2 : Chapter 14 : Section 2

21. Unit 2 : Chapter 14 : Section 2
Animals and Behavior
Hibernation, estivation, and migration help many animals survive in harsh conditions.
Unit 2 : Chapter 14 : Section 2

22. Selective Breeding
Selective breeding is the process of breeding plants and animals for particular genetic traits
Examples: pigeons, dogs, and cattle