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Adaptation

Investigation 3 – Lab

 

 

 

 

 

 

 

MINDSET

This Investigation is designed to:

  • demonstrate to you that environmental change that continues for a long enough time period can affect a species through natural selection,
  • allow you to observe the change in the allelic frequency of an advantageous trait as an environmental change persists over time,
  • demonstrate to you that possessing an advantageous trait allows a greater chance of survival during a time of environmental change,
  • demonstrate to you how an advantageous trait will become more common in a population as an environmental change continues, and
  • demonstrate to you that an environmental change can result in the extinction of a species if the species lacks a trait that could ensure its survival.

BE PREPARED

Student Preparation for the Investigation includes gathering the following materials. 

Note: The materials are listed in youyr SDR. They are also listed below for your reference.

  • (1) clear plastic container
  • (50) dark-colored gram cubes
  • (50) light-colored gram cubes
  • (2) 15 ml centrifuge tubes
  • (9) pinto beans
  • (6) sunflower seeds
  • (1) metric ruler
  • (1) stopwatch
  • (1) pair of forceps
  • (1) triple beam balance
  • sand
  • paper
  • fitted construction paper
  • (13) balloons
  • (1) plastic bucket
  • (1) calculator

Have one student from each lab group collect the materials listed in their SDR.

INVESTIGATE

  • In this Investigation, you will investigate how environmental pressure affects the survival of a species. In the model, the environment continues to become colder. Again, increased bone density in a penguin species is the recessive allele, and decreased bone density is the dominant allele.
  • Reflect on the PreLab video as you move through the procedural steps.
  • During the Experiment, every procedural step is important. If one step is skipped, data can become invalid. To help you keep on track, read each step thoroughly, complete the step, then check it off (Read it – Do it – Check it).
  • Complete all of the procedural steps in your SDR.

Note: The procedural steps are listed below for your reference.

Trial 1:

  1. Imagine: Recall from Investigation 2 the model world of penguins. In this model world, the weather has continued to get colder. It is now so cold that the water is freezing and there is barely any food left. Only 9 penguins have survived the new conditions. Through the process of natural selection, there are now more penguins with more dense bones compared to penguins with less dense bones. Of the surviving penguins, 6 penguins have more dense bones and 3 have less dense bones.
  2. Make the penguins that exist in the model world.

A. The penguins will be represented by gram cubes as in Investigations 1 and 2. Use the key in Table A for reference.

B. Connect two dark-colored gram cubes to make a penguin with two dominant alleles. This penguin has less dense bones. Make a total of 1 penguin with two dominant alleles.

C. Connect two light-colored gram cubes to make a penguin with two recessive alleles. This penguin has more dense bones. Make a total of 6 penguins like this.

D. Connect a dark-colored gram cube with a light-colored gram cube to make a penguin with one dominant allele and one recessive allele. This penguin has less dense bones. Make 2 penguins like this.

E. There should be a total of 9 penguins.

 

  1. Create the model ocean. Fill the clear plastic container with water until the water is 3-4 centimeters from the top of the container.
  2. Place 2 pinto beans into the container. These are fish that live deep in the ocean.
  3. Place 1 sunflower seed into the container. This is a fish that lives on the surface of the ocean.
  4. Place 8 empty balloons into the container. These represent ice chunks in the ocean.
  5. Separate the 9 penguins into two groups.

A. Remove the Genotype and Phenotype Page at the end of Investigation Three and place it on the table. This page will be used to help keep track of the different types of penguins.

B. Group A has 6 penguins and has more dense bones. Place these on the appropriate phenotype box of the Genotype and Phenotype Page.

C. Group B has 3 penguins and has less dense bones (homozygous dominant and heterozygous dominant). Place these on the appropriate phenotype box of the Genotype and Phenotype Page.

8. Go fishing for the 6 penguins with more dense bones.

A. One student will take the stopwatch and will keep time.

B. A second student will take the forceps and prepare to go fishing.

C. When the student keeping time says “go”, the person with the forceps will have 25 seconds to catch as many pinto beans and sunflower seeds as possible.

9. Record: Count the number of fish caught in 25 seconds. _________

10. Record: Calculate how many penguins survived.

A. It takes one fish to feed each penguin. Therefore, the number of penguins that survived is equal to the number of sunflower seeds or pinto beans caught.

B. There were 6 penguins at the beginning of the expedition.

C. Have one person hold all 6 pairs of gram cubes in their hands. Remember that each pair of gram cubes represents a penguin.

D. Another student will close their eyes and turn to the person who is holding the 6 pairs of gram cubes.

E. The student with their eyes closed will pick up enough pairs of gram cubes to equal the number of penguins that survived. For example, if 3 penguins survived, the student will pick up 3 pairs of gram cubes.

F. Place the penguins that starved to death in the “Dead Penguins” box of the Genotype and Phenotype Page.

G. Place the gram cube pairs for the penguins that survived back under the genotype box on the Genotype and Phenotype Page.

H. Record the total number of penguins that survived in Table B.

 

11. Place the pinto beans and the sunflower seeds that were caught back into the tank.

12. Now fish for the penguins with less dense bones.

A. Place the gram cubes that represent the 3 penguins with less dense bones aside into a pile.

B. The penguins with less dense bones can only eat the food on the surface of the water.

C. One person will be the timekeeper and one person will have the forceps.

D. When the timekeeper says go, the person with the forceps will have 25 seconds to catch as many sunflower seeds as possible.

13. Record: Count the number of fish caught in 25 seconds __________.

14. Record: Calculate how many penguins survived.

A. It takes one fish to feed each penguin, so the number of penguins that survived is equal to the number of sunflower seeds caught.

B. There were 3 penguins at the beginning of the expedition.

C. Have one person hold all 3 pairs of gram cubes in their hands.

D. Another student will close their eyes and turn to the person who is holding the 3 pairs of gram cubes.

E. The student with their eyes closed will pick up enough pairs of gram cubes to equal the number of penguins that survived. For example, if one penguin survived, the student will pick up 1 pair of gram cubes.

F. The student will then separate the surviving gram cubes into the correct genotype. Place the surviving penguins in the appropriate genotype box in the Genotype and Phenotype Page.

G. Place the penguins that starved to death in the “Dead Penguins” box of the Genotype and Phenotype Page.

H. Record the total number of each surviving genotype of penguin in Table B.

 

  1. Why did some of the penguins die? 
  1. Of the surviving penguins, is there a greater number of penguins with more dense bones or less dense bones? 

Adapt Inv. 3 Lab Conclusion Trial 1

  1. Why did the number of fish change? 
  1. How did the change in the environment affect the penguins? 
  1. Why did a greater number of penguins with more dense bones survive than penguins with less dense bones? 

Trial 2:

  1. In this Trial, you will analyze the alleles of the offspring of the surviving penguins.
  2. The surviving penguins will randomly mate.Adapt Inv. 3 Lab Trial 2 A

A. Place the gram cubes representing all of the alleles of all the surviving penguins in a pile.

B. One student should close their eyes and pick two pairs of gram cubes. This represents a pair of penguins.

C. Place the pairs aside.Adapt Inv. 3 Lab Trial 2 B

D. The student will again pick two pairs and put them aside into a separate pile.

E. The student will continue picking pairs until there are no more cubes left. If there is only one penguin left, place this one aside by itself.

3. Each penguin pair will produce one offspring.

A. Take one of the pairs, separate the cubes and place them on the boxes above and beside the blank Punnett square in Table C.

B. Find all four possible combinations of alleles using Table B. Hint: Often, many of the four combinations will be the same.Adapt Inv. 3 Lab Trial 2 C

C. Make these combinations by connecting gram cubes (there should be extra gram cubes provided). These are the possible babies that could occur.

D. One student should place the four possibilities into theirAdapt Inv. 3 Lab Trial 2 D hands.

E. Another student should close their eyes and randomly choose one of the four combinations. The one chosen will be the new penguin baby.Adapt Inv. 3 Lab Trial 2 E

F. Set the baby penguin aside.

G. Reconnect the two-parent gram cubes and place these aside with the baby.

  1. Repeat the same procedure for the remaining pairs.
  2. Record: Now count all the types of penguins.

A. Count the number of penguins with two dominant alleles and record in Table D.

B. Count the number of penguins with one dominant and one recessive allele and record in Table D.

C. Count the number of penguins with two recessive alleles and record in Table D.

 

 

Adapt Inv. 3 Lab Trial 2 Conclusion

  1. Were there a greater number of penguins with more dense bones or with less dense bones? Why? 
  1. The climate continues to change, and the model world continues to get even colder. Food becomes more scarce.
  2. Repeat the fishing expedition.
    1. Adjust the food supply so that there is only one pinto bean in the container and zero sunflower seeds.
    2. Add five more balloons to the container. There are now a total of 13 ice chunks in the water.
    3. First fish for all the penguins with more dense bones.
    4. When the student keeping time says “go”, the student with the forceps will have 25 seconds to catch the one pinto bean.

9. Record: How many fish were caught in 25 seconds? _________

10. Record: Calculate how many penguins survived.

A. It takes one fish to feed each penguin. Therefore, the number of penguins that survived is equal to the number of sunflower seeds and pinto beans caught.

B. Have one person hold all the pairs of more dense gram cubes in their hands. Remember that each pair of gram cubes represents a penguin

C. Another student will close their eyes and turn to the person who is holding the gram cubes.

D. The student with their eyes closed will pick up enough pairs of gram cubes to equal the number of penguins that survived. For example, if 1 penguin survives, the student will pick up 1 pair of gram cubes.

E. Place the penguins that starved to death in the “Dead Penguins” box of the Genotype and Phenotype Page.

F. Place the gram cube pairs for the penguins that survived back under the genotype box on the Genotype and Phenotype Page.

G. Record: How many penguins survived? _________

11. Repeat the fishing expedition for all the penguins with less dense bones.

A. Place the one pinto bean back into the container. There are no sunflower seeds. Remember these penguins can only eat the sunflower seeds because they can not dive deep enough to obtain pinto beans.

B. When the timekeeper says “go”, the student with the forceps will have 25 seconds to catch the one pinto bean.

12. Record: Count the number of fish caught in 25 seconds. 

13. Record: Calculate how many penguins survived.

A. It takes one piece of food to feed a penguin, so the number of penguins that survived is equal to the number of sunflower seeds caught.

B. Did any of the penguins with less dense bones survive? 

14. How many total penguins survived? 

15. Will the species of penguins be able to reproduce? 

Adapt Inv. 3 Lab Trial 2 Summarize

  1. Think about the information in the Background sections of this Investigation. How did the continued change in the environment affect the penguin population? 
  2. What is the difference between extinction and natural selection? 

Adapt Inv. 3 Lab Trial 2 Look For

Trial 3:

  1. In this Trial, you will analyze the fossil record of past penguin populations that occurred near Antarctica.
  2. Make the first layer of the fossil record. Refer to Table E for help.

A. Empty the plastic container.Adapt Inv. 3 Lab Trial 3 A

B. Pour sand from the bucket into the container to form a thin layer of sand that barely covers the bottom.

C. Two fish that lived deep in the water were found in this fossil record. Place 2 pinto beans into the container. Place them towards the outside of the container so that they can be seen from outside the container.

D. Five fish that lived on the surface of the water were found in the fossil record. Place 5 sunflower seeds into the container.

E. Five penguins were found in this first layer of the fossil record. Place 5 pairs of gram cubes into the first layer. One of these pairs should have the phenotype for more dense bones (homozygous recessive), and four should have the phenotype for less dense bones (homozygous dominant or heterozygous dominant).

F. Place a piece of construction paper over this layer of the fossil record. This piece of paper represents a long period of time.

 

 

3. Make the second layer of the fossil record.

A. Pour a thin layer of sand into the container on top of the construction paper.

B. Five fish that lived deep in the water were found in the second layer of the fossil record. Place 5 pinto beans into the container.

C. Two fish that lived on the surface of the water were found in the second layer of the fossil record. Place 2 sunflower seeds into the container.

D. Five penguins were found in the second layer of the fossil record. Place 5 pairs of gram cubes into the second layer. Four of these pairs should have the phenotype for more dense bones (homozygous recessive), and one should have the phenotype for less dense bones (homozygous dominant or heterozygous dominant).

E. Place a piece of construction paper over this layer of the fossil record. This piece of paper represents a long period of time.

4. Make a third layer of the fossil record.

A. Pour a thin layer of sand into the container on top of the construction paper.

B. No fish were found.

C. No penguins were found.

5. Which layer is the oldest? 

6. Why are there no penguins or fish in Layer 3? 

Note: Each student lab group should label their fossil record with their team name. They will need to refer to them in PostLab.

 

CLEAN UP

Be sure to clean up your lab bench after you have completed your experiment.