Change Over Time Vocabulary Evolution Natural selection Adaptation

Change Over Time

Vocabulary • • • Evolution Natural selection Adaptation Scientific theory Variation Fossil Half-life Species Punctuated equilibrium Relative dating Gradualism Absolute dating

Evolution -a gradual change in a species over time

Natural selection -the process by which individuals that are better adapted to their environment are more likely to survive and reproduce than other members of the same species

Adaptation -a characteristic that helps an organism survive in its environment or reproduce

Scientific theory -a well-tested concept that explains a wide range of observations

Variation -any difference between individuals of the same species

Fossil -the preserved remains or traces of an organism that lived in the past

Half-life -the time it takes for half of the atoms of a radioactive element to decay

Species -a group of similar organisms whose members can mate with one another and produce fertile offspring

Punctuated equilibrium -the theory that species evolve during short periods of rapid change

Relative dating -a technique used to determine which of two fossils is older

Gradualism -the theory that evolution occurs slowly but steadily

Absolute dating -a technique used to determine the actual age of a fossil