1. March 12, 2018 EQ: How does natural selection affect gene frequency over several generations? Warm-Up: In genetics, we discussed selective breeding. In our new unit, EVOLUTION, hypothesize as to what you think “Natural Selection is…”
Agenda:
Warm-Up
Introduction to Evolution
Brief natural selection
BREEDING BUNNIES

2. Evolution
S7L5. Obtain, evaluate, and communicate information from multiple sources to explain the theory of evolution of living organisms through inherited characteristics. a. Use mathematical representations to evaluate explanations of how natural selection leads to changes in specific traits of populations over successive generations. b. Construct an explanation based on evidence that describes how genetic variation and environmental factors influence the probability of survival and reproduction of a species. c. Analyze and interpret data for patterns in the fossil record that document the existence, diversity, and extinction of organisms and their relationships to modern organisms.
Concepts to be covered:
EVOLUTION
Charles Darwin
Natural Selection
Evidence of Evolution
Environmental factors leading to evolution

3. Breeding Bunnies (aka: probability-based gene frequency analysis)
We have this concept called NATURAL SELECTION
That states that organisms that are better equipped for survival have a better chance of….?

4. That’s pretty straight forward isn’t it
That’s pretty straight forward isn’t it? I mean, imagine you’re in a soup eating contest. You have a fork and your buddy has a spoon…you aren’t going to win that contest.
Natural selection works in the same way only the winner lives, and the loser…well…
Let’s look at what affects this process.

5. Overproduction: This refers to the way many organisms produce way more offspring than can survive.
2. Competition: Food and other resources are limited, right? Offspring compete for this resources to survive. Competition is usually indirect, and only a few offspring survive long enough to reproduce.

6. 3. Variations:  members of a species differ from one another with regard to certain traits. Differences between individuals of the same species is called VARIATION.
4. Selection:  Some variations make certain individuals better adapted to their environment. Those individuals are more likely to survive and reproduce.

7. Overall, when the individuals that are better adapted reproduce, their offspring may inherit the allele for the helpful trait.
The offspring will be more likely to survive and reproduce because they got the good genes (alleles) for the good traits.
Then the offspring can pass on the allele to their offspring.

8. After a bunch of generations, more organisms within the species will have the helpful trait.
Over a long period of time, natural selection can lead to evolution.
How? Beneficial variations gradually build up within a species, while unfavorable ones disappear.
This lab will demonstrate how this happens.

9. Scenario
One of the hottest new pets on the market is furless bunnies. Your friend, who lives in England, has a thriving business breeding furless bunnies. Tragically, one day he came home to find all 30 of his furless bunnies had escaped into the forest next to his home.

10. He is having a very hard time catching his bunnies
He is having a very hard time catching his bunnies. He is concerned that his furless bunnies will not survive the harsh winter and that the large population of furred bunnies in the forest will breed with his bunnies.

11. He has called on you to help him determine what will happen to his population of furless bunnies if they were to remain in the wild.
You will examine how natural selection will affect the genotypes of phenotypes of the bunny population.

12. Instructions (record this information…you will be handing it in)
Problem: (EQ) How will natural selection affect the evolution of the bunnies over many generations?
Hypothesis: ____(Write your hypothesis here)______________________________________ __________________________________________
State what you would predict (if your hypothesis is true) about the frequency of F alleles and f alleles in the population of rabbits after 10 generations, where ff bunnies are selected against (do not survive).

13. 1. Collect materials: 30 black beans, 30 white beans, 1 bag, 3 dishes, a piece of construction paper and a marker.
2. The black beans represent the allele for fur, and the white beans represent the allele for no fur. The container represents the English countryside, where the rabbits randomly mate.
3. Label one dish FF for the homozygous dominant genotype. Label a second dish Ff for the heterozygous condition. Label the third dish ff for those rabbits with the homozygous recessive genotype.
4. Place 30 black and 30 white beans (alleles) in the container and shake up (mate) the rabbits.

14. 5. Without looking at the beans, select two at a time, and record the results on the data form next to "Generation 1." For instance, if you draw one black and one white bean, place a mark in the chart under "Number of Ff individuals." Continue drawing pairs of beans and recording the results in your chart until all beans have been selected and sorted. Place the "rabbits" into the appropriate dish: FF, Ff, or ff.

15. 6. The ff bunnies are born furless
6. The ff bunnies are born furless. The cold weather kills them before they reach reproductive age, so they cannot pass on their genes…
To represent the death of the furless bunnies, place the beans from the ff container into the GRAVEYARD before beginning the next round.

16. 7. Place the alleles of the surviving rabbits (which have grown, survived and reached reproductive age) back into the container and mate them again to get the next generation.
8. Repeat steps five through nine obtain generations two through ten. If working as a team, make sure everyone in has a chance to either select the beans or record the results.
9. Once you have determined the genotypes of each generation, calculate the phenotypes.
10. Graph your data.