E2020 Lab Report: Natural Selection for Birds

Natural Selection for the Birds

Purpose:
To determine which birds with which beaks survive best in their environment depending on the type of food available.

Question:
What is the effect of the type of food available on the frequency of different types of bird beaks? Hypothesis:
If the food type changes in the environment, then the amount of each type of bird beaks will change because birds with beaks more suited to the available food will be more successful over time.

Variables:
The independent variable of the lab is the type of food that is available to the birds. The dependent variable of the lab is the frequency of each type-size and shape-of beaks.

Materials:
100 sunflower seeds
100 raisins
100 grains of rice
2 forks
2 spoons
2 knives
Plastic cup

Procedure:
1. Gather around the edge of the table cloth, mixing the three groups fairly evenly.
2. Pick up food pieces only with your tool, using the pair of utensils in one hand, simulating the action of a beak.
3. Pick up one piece of food at a time, and put it in your cup (“stomach”) before picking another piece of food.
4. Keep your body off the table cloth and pick up food only within your reach.
5. Start only when the teacher says “Go” and finish when all food has been “eaten.”

Data—Environment with Equal Amounts of Insects, Seeds, and Fruit

Second Generation
Flock X
Flock Y
Flock Z
Insects Eaten

35
32
33
Seeds Eaten
34
46
20
Fruit Eaten
78
15
7
Total
147
93
60
Percentage
49%
31%
20%
Simulated Number of Birds in Flock for 3rd Generation
15
9
6

Data—Changed Environment with Equal Amounts of Insects and Seeds but No Fruit.
First Generation
Flock X
Flock Y
Flock Z
Insects Eaten
30
60
60
Seeds Eaten
27
93
30
Total
57
153
90
Percent
19%
51%
30%
Simulated Number of Birds in Flock for 2nd Generation
6
15
9

Second Generation
Flock X
Flock Y
Flock Z
Insects Eaten
15
100
44
Seeds Eaten
17
80
44
Total
32
180
88
Percent
11%
60%
29%
Simulated Number of Birds in Flock for 3rd Generation
3
18
9

Analysis:
Based on the data in the first table flock X consumes mostly fruit. When fruit was taken away there was a decrease in the number of birds that flock X contained. Flock Y consumes mostly seeds. There was no effect on flock Y when fruit was removed. Due to the fact that flock Z eats mostly insects, the flock was not affected by the removal of fruit.
Conclusion:
In this lab I learned about how favorable traits are important when nature selects what organism will survive and pass down its genes for the next generation to inherit, I also learned that most species learn to adapt to their environments so that they can have a favorable trait to be able to survive in their environment. I was able to observe that in the wilderness you need that favorable trait so that you are able to reproduce and pass down your genotypes for the next generation of you species to inherit. I gained useful skills such as how to determine the next generation’s population by analyzing results from experiments I conducted relating to the bird populations