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25 Cards in this Set
- Front
- Back
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evolution
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change in the herediatry features of a species over time
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what is a species?
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group of organisms whose members successfully mate & have fertile offspring
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what is a population?
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organisms of one species who live in the same place at the same time
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what was Lamark's hypothesis
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Jean Baptiste Lamark's hypothesis stated that aquired characteristics could be passed on to offspring
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what was lamark's example?
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giraffes started out w/ short necks & then aquired long necks
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what was the problem with his theory?
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his hypothesis was never tested by Lamark & evenutally others disproved it
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what was charles darwins theory?
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said that organisms w/ traits most favorable for their environment sruvived & passed these traits on to their offspring
*tested and is evoltion* |
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what is natural selection?
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tje process by which nature selects organisms best adapted 2 a given environment @ a particular time
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theory of evolution by natural selection
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variations exist within a species & these variations can be passed from generation to generation
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limiting factor
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any physical or biological factor that regulates the welfare of an organism
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explain the gradual chart
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things change gradually
a species might take thousands of years to change color, which is gradual evolution |
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explain the punctuated evolution chart
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periods of stability followed by periods of rapid change
things (changes) happen almost instantly |
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what are the different types of fossils
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imprint
mold cast petrifed |
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what is an imprint?
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formed by tiny bones, leaf veins, feathers as the soft part of decompose
*when you put your hand in wet cement to make a print that's an imprint* |
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what is a mold?
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formed by impressions of large bones that decompose leaving a negative space where the bone used to be
*when you take something out of cement the part left behind is the mold* |
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what is a cast?
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formed when the space left behind a mold is filled with minerals and sediment
*looks like the original bone* |
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what is petrified?
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formed when minerals replace decomposing tissue leaving a perfect replica of the organism in stone
*a rock that was once a living tree* |
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what is relative age?
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position of the fossil in the rock layers (stratum) indicates its age relative to other fossils found
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what is absolute age?
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actual age of the fossil determined by radiocative dating
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which is more accurate radioactive or relative dating?
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radioactive dating is more accurate (exact)
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what is a fossil?
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traces of dead organisms found in sedimentary rock
sedimentary rock is layers of sediment compacted to make a rock |
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why did ppl used 2 believe that species never changed?
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during human lifetime it appears that species do not change. scientists began to suspect that species do chang SLOWLY
took many years for scientists to discover evolution |
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who was charles darwin?
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he was a captains boy on the HMS
he observed & noted everything & created a detailed catolague. he collected plant animal & fossil specimens |
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was charles darwins observations accurate?
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no because he took bad notes
he didnt write down where and when he saw things (he wasnt specific enough) |
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what is a naturalist?
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someone who studies nature
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