what is wrong with ths explanation ?

Question

Here is a student's explanation of the evolution of the peppered moth.

At first, all peppered moths were light colored. When pollution began to darken the tree trunks, some light colored moths turned a little darker. These darker moths survived and passed on their darker coloration to their offspring. The offspring became even darker, and their offspring were darker still. This continued until all peppered moths matched the color of the tree trunks.

Answer 1

There were both light colored and dark colored Peppered Moths in the forests of England. When the tree trunks were lighter,before the industrial revolution, the dark moths were more obviously seen by predators and didn't produce as many offspring. Thus the light colored moths were most abundant form. When the tree trunks began to darken from smoke and coal dust from nearby factories, the lighter colored moths began to be preyed on more frequently. Because of their light colored wings against the dark wood they were more easily seen by predators. The dark colored Peppered Moths lived to reproduce and became the dominant form of Peppered Moth in the forest of England. It was changing environmental conditions and lack of camouflage that brought about the change in dominant coloration.

Answer 2

LOL.
What's wrong with this explanation is that he's postulating evolution of individual moths, rather than a change in gene frequency in a population of moths!

I'm a Neo-Lamarckian, but the observed phenomenon here does not get a Lamarckian explanation!

What he should have said:
Initially, the wild-type population of pepper moths comprised mostly light-colored individuals, with only a few variant darker-colored ones. Birds and other predators were able, by sight, to pick off and eat the darker-colored moths, for they did not match the tree trunks to which they clung.

Pollution darkened the tree trunks. The predators then picked off the light-colored moths, leaving behind the darker-colored variants, who were now better camouflaged against the darker colored tree trunks. The darker-colored moths were more successful in having children by dint of not being eaten, and passed the alleles for dark coloration to their offspring. These darker-colored variants therefore came to have a greater proportional make-up of the population of pepper moths. One can extrapolate that if the pollution persisted, then the population of pepper moths would be composed mainly of dark-colored moths, with only a few light-colored moths.

Answer 3

You must be from the UK to have been asked this question. The light colored moths were more in existence until pollution darkened the trees, therefore as the trees got darker the light colored moths got eaten and the darker moths increased in population. The light colored moths only darkened over time because they had the recessive gene trait.
Both light and dark moths were in existence at the same time, just as today you can still find darker moths because the pollution has stopped darkening the trees and the lighter moth population is back in greater numbers.