Survival of The

Survival of the Flattest

Utah State Core: STANDARD V: Students will understand that biological diversity is a result of evolutionary processes. Objective 1: Relate principles of evolution to biological diversity.

Background Knowledge: This is a good introductory activity to natural selection.

Objective: In this activity students will model natural selection. They will do this by acting as a predator and collecting “dots” in different environments. They will see how different characteristics allow some organisms to survive and reproduce in different environments.

Equipment and Supplies: 250 (50 of 5 different colors) paper dots per group of 4 students, tweezers (1 per student), clock, student sheets, small paper cups, 36, 60 cm x 60 cm pieces of fabric (any colors or scraps will work, however it is best to have a solid, and a very busy pattern, try to punch dots that will blend in with the fabrics ex. If you have a red swatch make sure you have red dots) You will also need to decide if you want all groups to have the same or if all groups will have different fabrics.

Safety Issues None

Duration: One class period (50 min.)

Procedures for Teachers 1. Obtain needed supplies (ask your Sewing teacher for scraps he/she may be able to help you) 2. Pass out student sheet 3. Have student collect their supplies. 4. Read through the background and purpose with the students. 5. Allow students to make their predictions 6. Have students complete the lab by reading through and completing the procedures with their groups 7. Discuss results with the class when all groups have finished.

Scoring Guide: Prediction: 2 points Data Tables: 4 points Analysis questions: 2 points each (20 points) Conclusions: 4 points Total: 30 points

Answers to Analysis Questions: 1. Answers will vary. The dots that were picked most were those that stuck out in some way, maybe the color stood out or the texture was easy to pick up. 2. Answers will vary. The dots that were picked up the least were those that blended into the surface. They were best fit for survival in the environment. 3. Answers will vary. 4. Natural selection is the survival and reproduction of individuals which are best fit for the environment. They pass on their genes with greater frequency, thus overtime the population will display the trait. It is driven by the environment because that is what allows some to survive. If an animal is born with longer fur in a cold environment it is better fit and will most likely live longer and have more offspring. If the environment were not cold the animal would not be more fit. 5. Answers will vary. Possible topics include: farmers select for bigger flowers in plants, dog breeders select for larger noses, shorter legs, better sight etc. 6. The colors in the fabric and the patterns in the fabric. 7. Answers will vary. They could include diseases like AIDS, malaria etc. 8. These things are not as pertinent because as humans we can control them for the most part. We build shelters, have heaters and air conditioners, wear clothing etc. 9. Answers will vary but could include things like migration or natural disaster. 10. Answers will vary.

Answers to conclusions:

Answers will vary but should include a detailed description of natural selection.

Student Page Survival of the Flattest

Name:______Period:______

Background: Natural selection is sometimes referred to as survival of the fittest. In any given environment some individuals within a population contain specific traits that make them better able to survive and reproduce in an environment. By reproducing more frequently those individuals pass on their genes to future generations. Overtime the frequency of the alleles that code for that specific trait (which makes the individual better fit) will increase in the population. This change over time is evolution.

Purpose: To see how natural selection might change a population.

Materials: cup with dots, tweezers, clock, different surfaces

Prediction: Which color will be picked up least often from the table? Which color will be picked up the most?

Procedure: 1. Shake the dots in the cup. 2. Number your surfaces 1-4 and describe each in the data section below. 3. Put surface #1 on your table. 4. Pour out the dots on the surface. Have one person time the other two or three people as they pick up the dots with tweezers. 5. When 30 seconds has gone by, stop. 6. Count the number, type of paper and color of dots that were picked up. Count the number of each color and type that was not picked up. Put them all back in the cup. 7. Repeat on three different surfaces.

Data: Surface # Description of Surface 1 2 3 4

Color of Dot # on Surface 1 # on Surface 2 # on Surface 3 # on Surface 4

Analysis: 1. Which dots were most picked on the table? Why?

2. Which were least picked on the table? Why?

3. Did the results on the other surfaces support the results from #1 and #2? Why or why not?

4. What is natural selection? How is it driven by the environment? Give an example.

5. Artificial selection is driven by human interaction instead of the environment. Natural populations contain variation or diversity. Humans take advantage of this diversity and select for traits they find desirable. They then breed organisms that display the desired trait. Over time the frequency of the trait increases in the population. What are 2 examples of artificial selection you can think?

6. Describe two factors in the environment that act as natural selectors for dots.

7. What factors in the human environment are selecting us?

8. Why do factors in the environment like temperature and weather not act as severe pressures for natural selection on humans?

9. What could the changing of the surfaces represent in an actual environment?

10. If you could select out a gene or genes in the human population, what would it/they be and why?

Conclusion: Please explain 2 things you learned in complete sentences.