Of course, I'm referring to the dog!

Tens of thousands of years ago there were no dogs, only wolves. At some time long ago man started to domestic wolves, perhaps starting with some young pups. Those that grew into acceptable members of the tribe were allowed to stay under man's care. Some of the wolves' offspring were as docile, or even more docile, as their parents. The most friendly and sociable of each litter of pups grew into the dogs that stayed with man's family. Over the millennia these wolves diverged into a unique breed that not only tolerated man but seemed to prefer the company. Man domesticated wolves to help him hunt, pull his sleds, protect his home and even shepherd his sheep!

More recently, dogs have been selected for very specific tasks, behaviours and appearances. There are now dozens of "breeds" of dogs and they come in a wide variety of forms.
The Alsatian, Great Dane, Retriever and Husky still retain the size and strength of wolves but their behaviour is much more "refined".
Some dogs are so different from wolves that we tend to forget about thier biological history and think of them as children in the family. They have been bred to produce some of most "unwolf-like" extremes - Dachshund, Pekinese, Chihuahua, etc.
All these are the product of thousands of years of artificial selection on wolves!

Although primitive man had an incomplete understanding of heredity, he was able to control the evolution of a select group of wolves and thus "design" dogs.

Some of man's actions have resulted in evolution by accident.

A classic example of natural selection in action is the evolution of the English Peppered Moth (Biston betularia). This story illustrates an example of "industrial melanism" in the United Kingdom. The materials that museums had been collecting over the centuries provide the data.

This image shows two forms of this moth. Moths collected before the industrial revolution were very light in colour. A dark (melanistic) form first appeared near Manchester in 1848. By the middle of the 20th century more than 90% of all English Peppered moths in polluted (industrial) areas were melanistic. However, the frequency of the melanistic months dropped after the Clean Air Acts were passed, and the light colour months have been increasing in frequency ever since.

What caused this pattern of change (from populations of moths that were mostly light to populations that were mostly dark and then back again to light coloured moths)?
Here's what happened.