Science Moth investigation?

Question

Figure 6.26 shows color variations in Biston betularia.
Using the information in Figure 6.26, explain how you think the process of natural selection changed the appearance of the population of peppered moths around Manchester.
Make your explanation as detailed as possible. Try to include an explanation of the origin of the first black moth and what happened to all the light-coloured moths.

See image 6.26 below
http://i31.photobucket.com/albums/c371/kungfukitty/moth.jpg

Answer 1

Wikipedia has all the info you need, just plug in Peppered Moth, and you'll be on your way.
Ok, as a summary, there are two colours in this moth, one black, one peppered (peppered is the normal colour of this moth). Normally, they rest on trees, where they blend in beautifully with the mottled bark. This means that if you are a black colour, you will be easily seen, and eaten by birds. So more peppered colours survive. During times of heavy pollution, the barks of trees darken, so the darker forms of moth are more difficult to see, and predominate, by having more offspring. When coal stopped being used in Manchester, the trees eventually became lighter, and the peppered form became more prevalent.

Here is a link which explains it.
.

Answer 2

The first black moth appeared as a genetic variation in the species, due to a mutation in the pigment gene of the moth. The cream colored moths made up the largest percentage of the peppered moths because it had the most successful camouflage, due to the lichen covered trees in the area. As the industrial revolution wiped out the creamy lichen which grew on trees in the surrounding area, the creamy moths had less places to hide and avoid predators. However the change in habitat benefited the black moths of the species, as they were now able to avoid predators more effectively against the backdrop of the darker barks, and the population of the black moths thrived in the area, increasing and spreading the genes of the successful moths more able to avoid predators. With little camouflage to protect them, predators find the lighter colored moths more easily which accounts for the decrease in the lighter colored moth population. Hence, natural selection weeded out the lighter moths as a species adapts to a changing environment.