VOCABULARY

adaptation: Characteristics or traits that allow a species to better survive in its environment.
evolution: Process in all plants and animals that transmits traits from one generation to the next; these traits are generally beneficial to the plant or animal's survival.
natural selection: Process through which evolution occurs; those plants/animal's with traits that are less likely to help that plant/animal survive and reproduce die; process of nature selecting traits that will help a plant/animal to reproduce with healthy offspring

BACKGROUND INFORMATION

Evolution is the gradual change in a species over geologic time, many thousands or millions of years. All organisms go about the business of survival in many different ways. Over time, those that have the best ways of dealing with the environment are those that have the best chance of surviving. For example, a whale with a thicker blubber layer will survive cold northern waters better than another with less blubber. The whale with the thicker blubber layer will survive to pass on this trait to its offspring, which will in turn pass the same trait on to their offspring. Over time, slowly but surely all whales of that species will end up with thicker blubber. Thus, the entire species will end up with thicker blubber. This is called natural selection and was first described by Charles Darwin, an English naturalist who lived in the nineteenth century.

Changes like these can take many thousands or millions of years. These changes are called adaptations.