It seems obvious that when Britain’s trees were covered in black coal soot during the industrial revolution that the numbers of black-colored peppered moths would increase. But several recent studies indicate that a change to black coloration in creatures in response to pollution, called industrial melanism, may not be directly related to camouflage.

How do you know when something has been engineered? One way to tell is to study the words used to describe its characteristic features. The Mt. Rushmore rock faces have different characteristics from the surrounding uncarved rock that don’t resemble portraits of American Presidents.