Lab: Modeling Kettlewell’s Study



Lab: Modeling Kettlewell’s Study

Name: _________________________________________ Date: _________________ HR: _______________

BACKGROUND

In some ways living things become a mirror of the changes in their surroundings. The British peppered moth is a recent example of this phenomenon. In the 1850’s most of the peppered moths near Manchester, England, were grey in color. Only a few black moths existed. Because the grey moths were almost the same color as the tree trunks on which they lived, they were nearly invisible to the birds that hunted them for food. Most of the black moths, however, were spotted by the birds and eaten. The species as a whole survived because of the grey moths. Then changes in the environmental conditions had a drastic effect on the moths that lived in the area.

As more factories were built in the area, soot from the chimneys blackened the tree trunks. The grey moths could now be seen against the tree trunks. The few surviving black moths, however, now blended in with the tree trunks. As a result, they survived. These moths produced more black offspring. In time, practically all peppered moths were black. Again, the species as a whole survived.

TESTABLE QUESTION

How does changing the background color affect the percent of dark moths compared to the percent of light moths that are consumed by birds?

HYPOTHESIS

If the back ground color is changed from light to dark then the birds will consume _______________________

_________________________________________________________________________________________

because __________________________________________________________________________________

_________________________________________________________________________________________

PROCEDURE

1) Get two plates, one covered in a dark background color and one covered in a light background color.

2) Get a hole-puncher and punch 50 circle of the light color paper to represent the light moths. Punch 50 circles of the dark paper to represent the dark moths. Get a bottle with a top for storing the circles when not in use.

3) Get a clothespin to represent the bird.

4) Get a cup to hold circles as they are removed with the clothespin.

5) Get a stopwatch to time the feeding rounds.

6) 1st round: place the 50 dark and 50 light circles on the light plate. This represents moths on trees before they were blackened with soot. One person should use the clothespin and stand looking straight down at the plate. One person should use the stopwatch to time 30 seconds. During the 30 seconds, the person with the clothespin must remove moths ONE AT A TIME from the plate and deposit them in a cup. The birds will choke and die if it eats more than one moth at a time.

7) Count how many light moths and how many dark moths were consumed and record in the data table.

8) Repeat steps 6 and 7 two more times for the 2nd and 3rd rounds.

9) 4th round: place the 50 dark and 50 light circles on the dark plate. This represents moths on trees after they were blackened with soot. One person should use the clothespin and stand looking straight down at the plate. One person should use the stopwatch to time 30 seconds. During the 30 seconds, the person with the clothespin must remove moths ONE AT A TIME from the plate and deposit them in a cup. The birds will choke and die if it eats more than one moth at a time.

10) Count how many light moths and how many dark moths were consumed and record in the data table.

11) Repeat steps 9 and 10 two more times for the 5th and 6th rounds.

12) Average data and graph as a bar graph.

DATA

|Trial |Dark moths eaten on light plate |Light moths eaten on light plate|Dark moths eaten on dark plate |Light moths eaten on dark plate |

|1 | | | | |

|2 | | | | |

|3 | | | | |

Average dark moths eaten on light plate: ___________ Average light moths eaten on light plate: __________

Average dark moths eaten on dark plate: ___________ Average light moths eaten on dark plate: __________

Graph as a BAR GRAPH.

CLAIM

_________________________________________________________________________________________

________________________________________________________________________________________

________________________________________________________________________________________

EVIDENCE

________________________________________________________________________________________

________________________________________________________________________________________

________________________________________________________________________________________

REASONING

_______________________________________________________________________________________

_______________________________________________________________________________________

_______________________________________________________________________________________

LIMITATIONS

________________________________________________________________________________________

_______________________________________________________________________________________

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download