2. Natural Selection and Adaptation…53

3. Theory of Evolution
Species adapt, or change, over time leading to new variations which will result in a new species or the species will become extinct.

4. Charles Darwin The Theory of Natural Selection.
Studied birds in the Galapagos

5. Galapagos Darwin made a trip to the Galapagos Islands
Studied animals on each island
Noted differences between the same organisms on different islands
Do they know where these islands are?

6. Blue footed boobie!

9. Finches Noted major differences between the beaks of finches
Thick beaks = eat nuts/fruits
Many nut/fruit-bearing trees
Thin beaks = eat insects
Islands with few nut/fruit-bearing trees

10. 5 points of natural selection
Population have genetic variations
Some variations are favorable.
More offspring are produced than survive
Those that survive have favorable traits (advantageous)
A population will change over time

11. Mutation
Changes in the DNA of organisms Can be cause by radiation/chemicals or naturally

12. Thin fur
Thick fur
Thick/thin fur
Thick fur keeps the bears warmer in the winter
Produce 3 cubs…only 1 survived
The thicker fur can survive the winter
Overtime, the thin furred bears will die and leave only thick fur bears

13. Slow ostrich
Fast ostrich
Slow/fast ostriches
FASTER ostriches can out run the jackals
1 egg, but many rodents eat the egg
The survivors are fast runners
The slow runners will all be killed and all you have left with is fast runners

14. The cactus on the right has thorns so animals will avoid it
The cactus on the left can not make seeds (no baby plants)
Yes, Natural selection has occurred. Nature selected for the cactus with thorns
The thorns increase the fitness of the cactus. The thorns keep the deer away, allowing the cactus to reproduce.

15. OPEN YOUR NOTEBOOKS TO PAGE 53 (we need to finish your notes from Monday)

21. Adaptation
Trait that helps an organism survive in its environment

22. Fitness How successful an organism is at reproducing.
NOT how long it lives
“Survival of the Fittest” = Survival of those who make a lot of babies
This would be an honors only slide

23. Who is the fittest?

24. Who is the fittest?

25. Have tons of babies at a time
Overpopulation
Have tons of babies at a time
Predators kill most offspring
More babies = more that survive

26. Mutation  New Genetic Trait  advantageous 
TOP OF THE PAGE
Mutation  New Genetic Trait  advantageous 
passed down to offspring  Evolution!!!
I am insistent that they know what DNA is and what happens when you change it – prep for high school