Term
| Irwin-What we need to study |
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Definition
how a single species changes through time
how a single species becomes two or more species
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Term
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Definition
| How a single species becomes two or more species |
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| types of natural selection |
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Definition
stabilizing selection
directional selection
disruptive selection
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Term
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Definition
occurs whena selective force favors memberes of apopulation near the mean for a trait
removes variation in the group
strong seleciton pressure in favor of a middle range of a selected variation
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Term
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Definition
| occurs when conditions favor organisms at one end or the other of the range of variation |
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Definition
| occurs anytime conditions change so that they average animals are at a disadvantage |
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Term
| two specific situations when chance events contribute to natural selection |
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Definition
genetic drift
founder effects |
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Term
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Definition
any change in the variation within a population that is a result of chance events rather than specific selection
occurs more frequently when a breeding population is small |
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Term
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Definition
can occur anytime a very small number of organisms are separated from other members of their species or arrive at a new habitat
like if the whole campus was hit by a devastating hurricane and only gray squirrels were left. |
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