If you set the values of homozygous-dominant-males to 100 and homozygous-recessive-females to 100, and all the other values of initial males and females zero, what would be the values of p and q?
Overview
In this lesson, students investigate how genetic drift affects the genetic constitution of a population over time.
Standards
Next Generation Science Standards
Computational Thinking in STEM
- Data Practices
- Analyzing Data
- Manipulating Data
- Visualizing Data
- Modeling and Simulation Practices
- Using Computational Models to Find and Test Solutions
- Using Computational Models to Understand a Concept
- Computational Problem Solving Practices
- Troubleshooting and Debugging
- Systems Thinking Practices
- Investigating a Complex System as a Whole
- Thinking in Levels
- Understanding the Relationships within a System
Credits
Unit co-designed by Sugat Dabholkar in consultation with Teresa Granito of Evanston Township High School
Acknowledgement
CODAP is a computational tool for data analysis and representation developed and built by The Concord Consortium at https://codap.concord.org/
The first four lessons are based on a Howard Hughes Medical Institute (HHMI) Biointeractive (https://www.hhmi.org/biointeractive/pocket-mouse-evolution)
Lesson 5 is based on the lesson Evolution in Action: The Galápagos Finches Authored by Paul Strode for Howard Hughes Medical Institute based on data collected by Peter and Rosemary Grant, Princeton University.
This work is supported by the National Science Foundation (grants CNS-1138461, CNS-1441041 and DRL-1020101) and the Spencer Foundation (grant 201600069). Any opinions, findings, conclusions, and/or recommendations are those of the investigators and do not necessarily reflect the views of the funding organizations.
Activities
- 1. Getting to know the model
- 2. Exploring the model
- 3. Performing an investigation using the model
- 4. A big idea
Student Directions and Resources
In this lesson, you will investigate how genetic drift affects the genetic constitution of a population over time. You will design and perform an experiment about genetic drift using a computational model to test your hypothesis.
1. Getting to know the model
You have already used this model. Answer the questions below to refresh your memory.
Question 1.1
Question 1.2
If you set the values of initial males and females as follows:
- initial-homozygous-dominant-males: 50
- initial-heterozygous-males: 100
- initial-homozygous-recessive-males: 50
- initial-homozygous-dominant-females: 50
- initial-heterozygous-females: 100
- initial-homozygous-recessive-females: 50
What would be values of p and q?
What about the frequencies of AA, Aa and aa?
Question 1.3
Do you think the model, in its current state, satisfies all the Hardy-Weinberg Law of Genetic Equilibrium conditions?
Question 1.4
Run the model for 15 generations with the conditions in the previous two questions. Note your observations.
Do you think that the Hardy-Weinberg law holds?
Question 1.5
Explain your answer to the previous question.
2. Exploring the model
Question 2.1
Set the total initial population to less than 80. Make sure that it is a mixed population and there is at least one member of each genotype and gender. Run the model for at least 500 generations. Note your observations.
Question 2.2
Repeat the experiment that you did for the previous question at least 10 times. Note down your observations.
Question 2.3
Describe any patterns that you might have observed in the data you collected.
Question 2.4
Why do you think the patterns observed above are happening? Explain your answer.
3. Performing an investigation using the model
Question 3.1
Write a question about genetic drift in the pocket mice population which can be answered using this model.
An example of such question would be, 'how does population size affect the extinction of an allele from the population?' or 'is it more or less likely for a recessive allele to go extinct as compared with a dominant allele?'
Question 3.2
Based on your exploration of the model, guess an answer to your question and state it in the form of a testable statement (hypothesis) - something that you can test using the model.
Question 3.3
Design an experiment to test your hypothesis. Explain your design.
Question 3.4
Perform the experiment. Describe your observations and explain whether those support your hypothesis or not.
* You can record your data in a word or excel file and upload it in the next question to support you answer.
Question 3.5
Upload a word, excel or any other file here if you have used it record and analyze data.
Upload files that are less than 5MB in size.
| File | Delete |
|---|---|
Upload files to the space allocated by your teacher.
4. A big idea
Question 4.1
Mention and describe a big idea that you learned in this lesson.
