1. Monday, December 19
Do Now Read pages in the Biology Textbook on the tables. Define: Artificial Selection and Natural Selection Assign Yourself Natural Selection Practice Questions Take Out Materials Biorganizer – Cornell Notes page 80 Title: NATURAL SELECTION

2. Objective B.7C, B.7d, & B.7e
The student is expected to analyze and evaluate how natural selection produces change in populations, not individuals. The student is expected to analyze and evaluate how the elements of natural selection, including inherited variation, the potential of a population to produce more offspring than can survive, and a finite supply of environmental resources, result in differential reproductive success. Analyze and evaluate the relationship of natural selection to adaptation and to the development of diversity in and among species.

3. Key Point #1: theory of evolution
Evolution: The process of change over time Specifically, a change in the frequency of a gene or allele in a population over time

4. Key point #1 Charles darwin
Father of Evolution
Proposed a mechanism for evolution, called natural selection
Darwin went on a 5-year trip around the world on the ship, the HMS Beagle
As the ship’s naturalist, he made observations of organisms in South America and the Galapagos Islands
Wrote a book, “Origin of the Species”

7. Key Point #1 cfu THINK-PAIR-SHARE What is evolution?
Why is Charles Darwin called the father of evolution?
What did Darwin study that brought him to his conclusion?

8. Key Point #2 natural selection
Natural Selection: Organisms that are best adapted to an environment survive and reproduce more than others Darwin’s Theory of Natural Selection occurs in four steps: Overproduction Variation Competition Selection

9. 1. Overproduction
Each species produces more offspring that can survive

10. 2. Variation
Each individual has a unique combination of inherited traits.
Adaptation: an inherited trait that increases an organism’s chances of survival

11. What adaptations do you see?

12. What adaptations do you see?

14. Why is Variation Important?
Because the environment changes.
The more variation within a species, the more likely it will survive
EX: If everyone is the same, they are all vulnerable to the same environmental changes or diseases
The more variation of types of species in an habitat, the more likely at least some will survive
EX: Dinosaurs replaced by mammals

15. Which community has a better chance of surviving a natural disaster?
Community A
Community B

16. 3. Competition Fitness: the ability to survive and reproduce
Individuals COMPETE for limited resources:
Food, water, space, mates
Natural selection occurs through “Survival of the fittest”
Fitness: the ability to survive and reproduce
Not all individuals survive to adulthood

17. 4. Selection
The individuals with the best traits / adaptations will survive and have the opportunity to pass on it’s traits to offspring.
Natural selection acts on the phenotype (physical appearance), not the genotype (genetic makeup)
Ex: When a predator finds its prey, it is due to the prey’s physical characteristics, like color or slow speed, not the alleles (BB, Bb)

18. Individuals with traits that are not well suited to their environment either die or leave few offspring.
Evolution occurs when good traits build up in a population over many generations and bad traits are eliminated by the death of the individuals.

23. Peppered Moth A
Which moth will the bird catch? B

24. KEY POINT #2 CFU Overproduction Variation Competition Selection
STOP AND JOT
In your own words describe Darwin’s four steps of natural selection.
Overproduction
Variation
Competition
Selection

25. Analysis of Population Composition
Guided Practice
Independent Practice
5 Minutes
Work with your partner to answer to questions on the next slides.
6 Minutes (Homework)
Work on your own to complete homework.

26. Example: Moths on trees
Peppered moths can be light or dark. This is an example of variation (different traits).

27. Example: Moths on trees
When trees had white bark, the ___________ moths survived better, because it was harder for predators like birds to see them.
Light moth
Dark moth

28. Example: Moths on trees
When trees had white bark, the light moths survived better, because it was harder for predators like birds to see them.
Tree trunk
Light moth
Dark moth

29. Example: Moths on trees
Since light moths survived better, they had more offspring. Since they had more offspring, most of the population was light colored.
Population Most moths are light.
Light moth
Dark moth

30. Example: Moths on trees
Due to pollution, the tree bark became dark. When this happened, the _____________ moths survived better.
Tree trunk
Light moth
Dark moth

31. Example: Moths on trees
Due to pollution, the tree bark became dark. When this happened, the dark moths survived better.
Tree trunk
Light moth
Dark moth

32. Example: Moths on trees
Since dark moths survived better, they had more offspring. Since they had more offspring, over time, most of the population became dark colored.
Population
Most moths are dark.
Dark moth
Light moth

33. Exit Ticket (7 min)
Students will have 7 minutes to silently complete the exit ticket, and SHOULD use their notes from class.