1. Do now activity
Why is it important to have variation within a species?
Give 2 examples of variation within ONE species.
Name 5 possible genes found in the human gene pool.
List 5 different species of living things.

2. Essential Question: Section 7-1: variation
Why does an advantageous trait increase in proportion within a species over time?
Learning Target
Justify why an advantageous trait will increase in proportion from one generation to another when provided statistical evidence.
Section 7-1: variation

3. Critical Readings must be stamped and turned in by Wednesday (2/8/17).
announcements
Biology Tutoring this week:
Lunch B (Tuesday & Thursday)
7:00AM (Monday – Friday)
After school Biology Tutoring: Tuesday
Critical Readings must be stamped and turned in by Wednesday (2/8/17).

4. announcements Available Extra Credit: Tissue Box = 2 Points
6.6oz bag of Goldfish (Pretzel/Cheddar) = 5 Points

5. Don’t forget to chunk your notes!

6. Variation = differences within a species
overview
Variation = differences within a species

7. Variation is needed for Natural Selection
overview
Variation is needed for Natural Selection

8. overview
Genetic Variation
Gregor Mendel
Charles Darwin

9. Population Evolution
A _____ is a group of organisms of the same species that can breed and produce fertile offspring.
Population
Individuals provide the variations
But…
Populations, not individuals evolve
Population: a group of individuals of the same species that can breed with each other
We study the genetic make up of a population to see if it changes

10. Population Evolution
A population is a group of organisms of the same species that can breed and produce fertile offspring.
Population
Individuals provide the variations
But…
Populations, not individuals evolve
Population: a group of individuals of the same species that can breed with each other
We study the genetic make up of a population to see if it changes

11. All the genes in a population is called a ___ ______ .
Population Evolution
All the genes in a population is called a ___ ______ .
Gene pool
We study the genetic make up of a population to see if it changes
gene pool: all the genes in a population
Because populations breed together they have the same gene pool

12. All the genes in a population is called a gene pool .
Population Evolution
All the genes in a population is called a gene pool .
Gene pool
We study the genetic make up of a population to see if it changes
gene pool: all the genes in a population
Because populations breed together they have the same gene pool

13. ____ _____ is the number of times an allele occurs in a gene pool.
Population Evolution
____ _____ is the number of times an allele occurs in a gene pool.
Relative Frequency
Evolution (genetic terms): any change in the relative frequency of alleles in a population

14. Population Evolution
Relative (gene) frequency is the number of times an allele occurs in a gene pool.
Gene/Relative Frequency
Evolution (genetic terms): any change in the relative frequency of alleles in a population

15. Population Evolution
What is an allele?
cyclins

16. Alleles are different forms of a gene.
Population Evolution
Alleles are different forms of a gene.
cyclins

17. _____ are different forms of a trait in a population.
Genetic variation
_____ are different forms of a trait in a population.
Alleles
Each gene has at least two alleles
Ex. brown or white fur

18. Alleles are different forms of a trait in a population.
Genetic variation
Alleles are different forms of a trait in a population.
Alleles
Each gene has at least two alleles
Ex. brown or white fur

19. There are 2 sources of genetic variation.
cyclins

20. Genetic variation
Change (mistake) in DNA code
Source #1: Mutations

21. Source #2: Gene Shuffling
Genetic variation
Gene shuffling
Meiosis followed by sexual reproduction
Most genetic variations are due to gene shuffling
In humans this produces 8.4 million different combinations of genes
Does not change the relative frequency of alleles in a population
Source #2: Gene Shuffling

22. Single gene & polygenic traits
# of phenotypes depends on # of genes

23. Single gene & polygenic traits
Frequency of Phenotype (%)
Phenotype
Single-gene traits have 2 phenotypes
Freckles No
Freckles

24. Single gene & polygenic traits
Frequency of Phenotype (%)
Phenotype
Single-gene traits have 2 phenotypes
Free
Earlobe
Attached
Earlobes

25. Single gene & polygenic traits
Frequency of Phenotype (%)
Phenotype
Dominant phenotypes may be less frequent in a population
No Widows
Peak
Widows
Peak

26. Single gene & polygenic traits
Most traits are polygenic.
Frequency of Phenotype
Phenotype
(height)

27. Single gene & polygenic traits
Most traits are polygenic.
Frequency of Phenotype
Phenotype
(height)

28. Single gene & polygenic traits
Most traits are polygenic.
Examples:
Human hair color
Human height
Human eye color
Frequency of Phenotype
Phenotype
(height)

29. Single gene & polygenic traits
Polygenic traits have more than 2 genes.
Frequency of Phenotype
Phenotype
(height)

30. Single gene & polygenic traits
When there are many variations, they are grouped in a symmetrical bell-curve
Frequency of Phenotype
Phenotype
(height)

31. Do now activity #1
What type of Natural Selection is selecting brown rabbits?
What type of Natural Selection is selecting for black AND white rabbits?
What type of Natural Selection is selecting for ONLY black rabbits?