Transcript Superposition Oldest on Bottom…Youngest on top

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Genetic change over time
Resulting in new species
There is more to evolution than change
Trees change, mountains change
Evolution is a change in genes that control
traits in an organism
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Natural…Nature chooses
Artificial Selection…Humans choose
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Natural selection has four basic principles:
1. More organism are born than can survive.
2. All of the organisms (offspring) will have
genetic changes due to sexual reproduction and
mutation
3. The environment doesn’t have enough resources
to support all of the individuals that are born.
4. Some of these changes will be beneficial to an
organism. These benefits lead to a stronger
organism and these stronger traits are pass
down to future generations.
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The environment changes
A trait which is good for one environment
may not be good for a different environment
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Brown rabbits vs. white rabbits
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Natural Selection:
Nature chooses
 Conditions in nature select for traits in
organism which will make that organism
the most successful.
 Selected for…Passed on
 Selected against…extinct
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All that you see are things that humans have
chosen
The stuff you don’t see are items we have not
selected for…they may become extinct...or
retro in twenty years.
Music, clothes, TV, etc. Anything “popular”
has been selected for. The unpopular…not
around.