Bio 104
2/15/13
Critique of the Pepperd Moth Experiment In the next few paragraphs I will be giving you two different types of experiments conducted. The first is going to be by Kettlewell and the second is by Rory Howlett and Michael Majerus. I will be explaining what they did in each of them as well as give you a conclusion and my own personal critique on each of them.
The Kettlewell Experiment In early Great Britain it was noticed that there was a depletion of the light colored peppered moths and an increase in the darker moths in the industrial areas of Great Britain, so, Bernard Kettlewell decided to conduct an experiment to find the true explination for this occurrence. First Kettlewell started to raise the moths in his laboratory so he can start conducting the experiments. So he could recognize them, he put a small mark on each of their wings and also to make the experiment a little easier. He then released the moths in different areas. The first area he made sure to release them where there was pollution which was Birmingham city. The other area he released them was in a different wooded area but this time he made sure to release them more near a farming area where there was much less pollution. After doing all of this Kettlewell then set traps(some made of zinc and others made of muslin) all around the woods to catch the moths and see which ones came back in the larger numbers to conclude his experiment. He found that the darker moths were the ones that survived closer to the city where the trees and the area was darker in general, and the lighter moths thrived further away from the city where the trees were lighter (pg 331-335 on kettlewell paper). Kettlewell then ended up concluding that the pollution from the city caused the trees to become darker (industrial melanism) and in turn helped the darker moths to survive.
Howlett and Majerus
In this paper they conducted a pilot test to see if the disappearance of the moth simply had