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“LIFE CHANGES OVER

TIME “STUDY GUIDE

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A species is a group of organisms that look

alike and can reproduce among

themselves.

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Evolution is the process by which

species change over time.

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An adaptation is a feature or trait that helps an organism

to live in a certain environment.

The giraffe’s neck has grown longer over time so it can eat leaves that

grow at the tops of trees.

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A sudden change in a gene is called a

mutation. It can be harmful

or helpful .This albino snake’s mutation makes it more vulnerable to

predators.

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Animals or plants that no longer exist are said

to be extinct.

Animals like this dinosaur no

longer live on earth because

they’re extinct.

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Fossils are the remains or traces of

once-living organisms.

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Amber is fossilized tree sap in which

ancient insects are sometimes preserved.

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Homologous structures are body parts that have the same basic structure like the arm of a human, the leg of a cat, the

flipper of a whale, or the wing of a bat.

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Vestigial structures are body parts that

seem to have no function like a human

being’s appendix.

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Darwin’s theory of natural selection is that offspring with the most

favorable traits survive and reproduce.

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Differences in traits among organisms in a

species is called variation.

There are variations in the color of these Sweet

William flowers.

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Anthropology is the study of human

beings.