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Evolution
Question | Answer |
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species | a group of similar organisms whose members can mate with one another and produce fertile offspring |
evolution | the 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 |
sedimentary rock | a type of rock that forms when particles from other rocks or the remains of plants and animals are pressed and cemented together |
relative dating | a technique used to determine which of two fossils is older |
absolute dating | a technique used to determine the actual age of fossils |
half-life | the time it takes for half of the atoms of a radioactive element to decay |
fossil record | the millions of fossils that scientists have collected |
extinct | a species that does not have any living members |
gradualism | the theory that evolution occurs slowly but steadily |
punctuated equilibria | the theory that species evolve over short periods of rapid change |
homologous structure | body parts that are structurally similar in related species; provide evidence that the structures were inherited from a common ancestor |
branching tree | a diagram that shows how scientists think different groups of organisms are related |