Peppered Moths

Natural Selection YES Evolution NO.

In my BIO 101 class this month we have been covering the long standing theory of evolution. The Dictionary.com definition for evolution is:

ev·o·lu·tion
A gradual process in which something changes into a different and usually more complex or better form. The process of developing. Gradual development.
Biology:Change in the genetic composition of a population during successive generations, as a result of natural selection acting on the genetic variation among individuals, and resulting in the development of new species. The historical development of a related group of organisms; phylogeny. A movement that is part of a set of ordered movements.
Mathematics. The extraction of a root of a quantity.

With the Biological definition being: A change in the genetic composition of a population during successive generations, as a result of natural selection acting on the genetic variation among individuals, and resulting in the development of new species. I don't see what the peppered moths to do with the "Origin of Species".

Here is the full title of Darwins book:
ON THE ORIGIN OF SPECIES BY MEANS OF NATURAL SELECTION, OR THE PRESERVATION OF FAVOURED RACES IN THE STRUGGLE FOR LIFE.