1. 10/13 HOMEWORK
10/13 homework: Finish page in the blue workbook and on page 32 in your notebook take notes on Genetic drift and gene flow. I will check tomorrow.

2. 10/13 Daily Catalyst Pg. 31 Mutations
1. In a population in HWE, 32% of the people have green hair (recessive trait) and 68% of people have purple hair (dominant trait). Over the next five years, how would you expect the percentage of hair color to change?
2. What three HWE conditions cannot be met? Why can they not be met?
3. What can you assume about analogous structures and their DNA?

3. 10/13 Daily Catalyst Pg. 31 Mutations
1. In a population in HWE, 32% of the people have green hair (recessive trait) and 68% of people have purple hair (dominant trait). Over the next five years, how would you expect the percentage of hair color to change?
The percentages will not change! HWE!
2. What three HWE conditions cannot be met? Why can they not be met?
Mutations, Natural selection, and random mating
3. What can you assume about analogous structures and their DNA?
These organisms do not share a percentage of DNA. They JUST live in the same environment

4. 10/13 Daily Catalyst Pg. 31 Mutations
Class Business
Homework review
Mutation Notes

5. HW Review

6. 10/13 Daily Objective Pg. 31 Mutations
We will be able to connect evolutionary changes in populations over time to a change in the environment.

7. Key Point #1: A change in the gene pool is called microevolution.
Recap
On Friday, we discusses gene pools and gene frequencies. The gene pool is the total collection of genes in a population at a time.
When gene frequencies change, this is evolution occurring at the smallest scale.
Key Point #1: A change in the gene pool is called microevolution.

8. Genetic Variation
We have no problem picking out our friends and family in a crowd because of the variation in traits.
Not all variation is heritable.
Provide an example of this:
Muscle mass and tattoos

9. Key Point #2:
ONLY THE GENETIC COMPONENT OF VARIATION IS RELEVANT TO NATURAL SELECTION.

10. Darwin’s Observations
There is variation within a given species and the majority of this variation is inherited. This litter of kittens vary with respect to coat pattern and color.
Any variation may, to some degree, affect the ability of an organism to reproduce and contribute genes to the gene pool, thus affecting evolutionary success.
Species change over time. These changes are related to traits that are inherited or arise from an alteration of the genetic code.
Some inherited traits are beneficial and contribute to survival.
Whether a trait is beneficial or not is a function of the environment in which it lives.
Emphasize that there is a difference between heredity and mutation.

11. Adaptations and Fitness
An adaptation is a genetically controlled trait that is favored by natural selection and gives the organism a reproductive advantage ensuring the trait is passed on to its descendants.
This trait may also allow the individual to survive longer thus increasing the reproductive rate of that individual.
Ask students to compare these two hares and identify the differences in their traits. The students should come up with coat color, length of ears, length of limbs, body shape, etc.

12. Adaptations and Fitness
The antelope hare lives in the desert, and the snowshoe hare lives in the mountains.
Explain how the differences in their traits enhance their ability to survive in their respective environments.
Evolutionary success or fitness refers to the contribution of genes to the gene pool and NOT how long an organism lives.
It’s one thing to “identify” traits and yet another to explain their importance or implication!
The long limbs of the antelope hare help dissipate body heat and keep the hare cool. The brown coat color helps it to blend in with its environment, thus be less obvious to potential predators. The snowshoe hare has smaller ears and shorter limbs with a rounder body. This helps keep the hare warmer. The white coat color helps it to also blend in with its environment.

13. The Effect of Environmental Change
Earth’s environment is NOT STATIC, but rather ever changing.
As a consequence, traits or adaptations that were favorable may become unfavorable.
The peppered moth, Biston betularia is native to England and exists in two forms, one is dark and the other light with a “peppered” appearance. Birds are its main predator.
Prior to the industrial revolution, only 2% of the moths were dark.
The industrial revolution produced vast amounts of sulfur dioxide and soot from the burning of coal which altered the environment.
Fifty years later 95% of the moths were dark.
Propose an explanation!
Environmental changes often cause a shift in selection pressures. Traits that were once beneficial to a population of organisms may become detrimental and vice versa.

14. Industrial Melanism
England has since regulated the burning of coal and as a result, the trees are returning to their original state (A).
Consequently, the coloring among the population of moths in Britain has shifted back so that the peppered moths are once again favored.
Explanation: The trees were previously light and covered in lichens, thus peppered moths had the advantage of camouflage over dark moths. (You may have to point out the peppered moth near the top of photo A.)
The SO2 gas produced from the industrial revolution killed the lichens. Furthermore, the soot produced during the burning of coal collected on tree trunks changing their appearance and darkening them. As a result, the darker moth is now more camouflaged and less likely to be eaten by birds.

15. Evolution Defined
Evolution is defined as a change in the inherited characteristics of biological populations over successive generations.
Evolutionary processes give rise to diversity at every level of biological organization, from the molecular to the macroscopic.
As a result diversity is prevalent among molecules such as DNA as well as individual organisms and species of organisms.
Students need to be clear on the approaching definitions and distinctions AND have some illustrative examples they can discuss on the AP Exam.

16. Microevolution
Microevolution is simply a change in gene frequency within a population.
Evolution at this scale can be observed over short periods of time such as from one generation to the next.
Example: The frequency of a gene for pesticide resistance in a population of crop pests increases.
Such a genetic change might come about because:
natural selection favored the gene
the population received new immigrants carrying the gene (gene flow)
nonresistant genes mutated into a resistant version of the gene
or random genetic drift from one generation to the next
Remind students that a gene is a sequence of DNA nucleotides that specify a particular polypeptide chain and that genes code for proteins.
Have students generate an example for each of the 4 example “causes” of microevolution. Many correct answers are possible!
natural selection favored the gene (sickle cell anemia & malaria)
the population received new immigrants carrying the gene (light skinned population crosses with dark skinned population resulting in hybrids)
some nonresistant genes mutated to the resistant version (natural immunities to disease among populations)
because of random genetic drift from one generation to the next (founder effect)

17. Microevolution
A gene is a sequence of DNA nucleotides that specify a particular trait.
An allele is a different version of a gene For example: black coat color or white coat color
B represents the allele for black coat color and b for white coat color.
Key Point #3: Natural selection acts on individuals, but only populations evolve.
Really emphasize those last two bullets! When students write about evolution it is VERY important that they can “say what they mean and mean what they say”. These last two bullets belong in the response to any evolution free-response question!

18. Remember last week when I told you your DNA determines your inward and outward appearance?
Genotype: genetic make up (gene for type O blood)
Phenotype: expression of traits (eye color)
Selection acts on phenotype because differential reproduction and survivorship depend on phenotype not genotype. Do you have what it takes to survive?

19. Sources of Genetic Variation
How does variation in a population or gene pool arise?
MUTATIONS!
The wisteria pictured on the right has a mutation causing it to produce white flowers instead of purple flowers.
Emphasize the importance of meiosis and sexual reproduction as the driving force of evolution. Meiosis is responsible new phenotypic combinations upon which natural selection can act.
Meiosis recombines alleles in new combinations  which results in unique gametes due to the way chromosomes line up on the metaphase plate and crossing over.  Meiosis coupled with fertilization produces offspring with different combinations of alleles.  The genetic complement that the zygote receives will be different from either parent and  is different from any sibling.   Identical twins are genetically identical to one another but the likelihood that two siblings (not identical twins) will be genetically identical is extremely remote 223 x 223.  Tell students that the genetic “shuffling” during meiosis is like getting a new hand when playing cards.

20. Types of Mutations
Key Point #4: Only mutations occurring in gametes affect future generations.
Gamete cell, what?!
SEX CELLS (sperm and egg)
Obviously, mutations occurring in somatic cells do not affect future generations.
Somatic cells, what?!
All the rest of your cells (bones and skin)
Emphasize that mutations lead to genetic variation. These next slides explain each of these mutation types. Students should have prior knowledge of genes, DNA, and mutations from Pre-AP Biology.
Mutations may cause a sheep to have a 5th leg. But this is not evolution! 

21. Mutations can occur at either the gene or chromosomal level.

22. Point/Substitution Mutations
Key Point #5: One nucleotide is substituted for another.
If this mutation does not affect the function of the protein, then this mutation is harmless.
AKA silent mutations

23. The genetic code is repetitive
The genetic code is repetitive. Different variations of the nucleotides still code for the same protein. So as long as the same protein is made, everything is ok!

24. Some mutations may add or delete nucleotides therefore affecting the protein that is coded for.

25. Frameshift Mutation
Key Point #6: A frameshift mutation occurs as a result of either an insertion or deletion of a nucleotide.
AKA insertion mutation
AKA deletion mutation
This changes the amino acid sequence of the protein from that point forward. This has a huge effect!

26. What are my chances?
Mutation rates in eukaryotic cells average about one in every 100,000 genes per generation.

27. What else can alter a population’s genetic composition?
Genetic Drift:
Bottleneck Effect
Founder Effect:
Gene Flow