Monday, November 25, 2013

11/25/13

Tonight's homework is to complete Assignment 21 and read/takes notes on 8.3 "Biological Evolution" (p. 149-154) in Botkin and Keller).

Assignment 21 Simulating Natural Selection

Procedure


1. Go to the class website (www.sofenvironmentalscience.blogspot.com) and click on the Natural Selection Simulation link.


2. Read the directions for the simulation and/or experiment with it for 2 minutes until you get an idea of how it works and how you can change variables/settings.


3. You will be controlling the mutations and environment of a population of rabbits. You will create three hypotheses and design an experiment to test each one. Your hypotheses should each answer the following question:


How does ___________________ (the selection factor of your choosing) affect the survival of rabbits with _________________ phenotype (the mutation you choose) within __________ environment (the environment you choose)?


You should make a hypothesis for EACH of the three different types of phenotype mutations. Each experiment must also have a control group.


4. In your lab notebook, set up a data table to record how the population and its genes/traits will change over the course of the simulation. Here is a sample:


Hypothesis
Phenotype
Selective Factor
Control Group
Initial Pop. at Generation 3
Control Group Final Pop.
Experimental Group Initial Pop. at Generation 3
Experimental Group Final Population









5. Choose your options for the different variables (mutation and environment, but NOT selection factor yet). Also be sure to “Add a Friend.”


6. Start working through the simulation and pause after the third generation and record the populations of each phenotype as the “Initial Population.” At this point, you should now click on the selection factor of your choice. Continue the simulation for 3 or 4 more generations, pause again and then record the populations of each phenotype as the “Final Population.”


7. Make inferences about what happened during the simulation.


8. When finished, reset the simulation, and test your next hypothesis.


Analysis Questions


Answer the following questions to the best of your ability in complete sentences in your lab notebook.


1. Evaluate each of your hypotheses. Support your conclusions.


2. Sometimes animals are introduced into an area that they never lived in before outcompete and endanger native species. These introduced species are called invasive species. Why do you think that this phenomenon occurs?


3. How did the simulation(s) you viewed demonstrate evolution and natural selection? Be specific and thorough.


4. Use one of the simulations that you created and viewed to explain why biodiversity is necessary for natural selection and evolution.

5. EXTENSION (for extra credit) – Recreate one of your experiments, except that when you add the mutation you should edit the genes by switching the dominant and recessive allele for that trait. Make a hypothesis and a new chart (or add to your old chart) and compare your results to your initial experiment.


Natural Selection Simulation - after accessing the link, you may need to click on "Download" (as opposed to "Run").

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