World Population and Beak Size
Before you undertake this assignment, please read carefully the handout that gives an overview of EvolutionLab. This will make it much easier for you to understand the assignment and complete it correctly.
1. There are many ecological and biological factors that affect evolution. In EvolutionLab, two populations of finches are tracked over the course of 300 years on two different islands to see how changing the traits of the birds and their environment affect their long term viability as a sustainable population. Let’s begin by doing a “null experiment” where conditions are identical on the two islands.
Set the “revisit in” drop-down menu to 300 years and then click the Run Experiment button. Click the Input Summary tab and note that in this experiment and note that all factors (both biological and ecological) were identical. Then click the Beak Size tab. Which of the following is true? (Keep in mind that the term “rate” refers to how fast, not how much. Also, we are looking for major differences, not minor ones due to random chance.)
a. When all factors are equal, the beak size of both species increased at a different rate over 300 years.
b. When all factors are equal, the beak size of both species increased at roughly the same rate over 300 years.
2. Click the Population tab. Which of the following is true?
a. The finch populations of both islands increased at roughly the same rate over 300 years.
b. The finch populations of both islands increased at different rates over 300 years
3. Based on the results for beak size and population numbers, what can you conclude about evolution when all factors are equal?
a. While the populations both increased in size, mean beak size did not. Therefore, when all factors are equal, evolution does not occur.
b. The mean beak size of both populations increased. Therefore, under these circumstances, evolution did occur in both species.
c. Neither (a) nor (b).
4. Click the New Expt button and then click the
1. There are many ecological and biological factors that affect evolution. In EvolutionLab, two populations of finches are tracked over the course of 300 years on two different islands to see how changing the traits of the birds and their environment affect their long term viability as a sustainable population. Let’s begin by doing a “null experiment” where conditions are identical on the two islands.
Set the “revisit in” drop-down menu to 300 years and then click the Run Experiment button. Click the Input Summary tab and note that in this experiment and note that all factors (both biological and ecological) were identical. Then click the Beak Size tab. Which of the following is true? (Keep in mind that the term “rate” refers to how fast, not how much. Also, we are looking for major differences, not minor ones due to random chance.)
a. When all factors are equal, the beak size of both species increased at a different rate over 300 years.
b. When all factors are equal, the beak size of both species increased at roughly the same rate over 300 years.
2. Click the Population tab. Which of the following is true?
a. The finch populations of both islands increased at roughly the same rate over 300 years.
b. The finch populations of both islands increased at different rates over 300 years
3. Based on the results for beak size and population numbers, what can you conclude about evolution when all factors are equal?
a. While the populations both increased in size, mean beak size did not. Therefore, when all factors are equal, evolution does not occur.
b. The mean beak size of both populations increased. Therefore, under these circumstances, evolution did occur in both species.
c. Neither (a) nor (b).
4. Click the New Expt button and then click the