Artificial selection can produce dramatic change.

A kind of artificial selection has generated almost all our agricultural crops and domestic pets. No doubt the artificial selection in these cases - begun thousands of years ago in some cases - employed less formal techniques than would a modern breeder. However, the longer time span has led to some striking results, such as the enormous variety in domestic dogs.

The point here of these, and similar, examples is to illustrate further how, on a small scale, species can be shown experimentally not to be fixed in form.

The labrador dog opposite is the result of thousands of years of artificial selection.