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Darwin and Natural Selection

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Presentation on theme: "Darwin and Natural Selection"— Presentation transcript:

1 Darwin and Natural Selection

2 Charles Darwin (born 1809) -sailed on the HMS Beagle for 5 years studying organisms around the world (many in the Galapagos) -Noticed similarities amongst organisms around the world (wanted to know how)

3 Artificial Selection Noticed that humans grow crops and breed animals to get the most useful traits in offspring (ex. cows with more milk, biggest vegetables,) -called this artificial selection.

4 Charles Darwin -Concluded that natural selection can occur too .
-1. organisms in a population vary in traits -2. these traits can be passed on to offspring. -3. more are born than the environment can support -4. the ones with the best traits live to pass them on Ex. Sharp teeth in sharks

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6 Natural Selection -natural selection -change in populations traits over time (must be heritable [in genes]) -selective pressure – factor that makes a trait favorable (predator, habitat, food source, etc). -fitness level- how equipped an organism is for survival and reproduction

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8 Adaptations -inherited traits that increase organisms’ chances of survival (color, claws)

9 Structural Adaptations
-physical structures that increase an organism’s fitness level

10 Coloration Camouflage- blend in with surroundings
Mimicry- imitate other organisms

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12 Ornamental -structures that attract mates

13 Physiological Changes in the body to increase fitness level (ex. immunity)

14 Behavioral -behaviors that increase fitness

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