teacher presentation to teach natural selection to middle school students with check for understanding questions

1. A Closer Look At Darwin’s Idea
of Natural Selection

2. Natural Selection Rests on 4 Elements:
1) There is _______ (differences) in the
traits of individuals within a population

3. Natural Selection Rests on 4 Elements:
1) There is variation (differences) in the
traits of individuals within a population

4. Natural Selection Rests on 4 Elements:
1) These are all rabbits with varying
(different) ______.

5. Natural Selection Rests on 4 Elements:
1) These are all rabbits with varying
(different) traits.

6. Natural Selection Rests on 4 Elements:
2) There is difference in survival
 some survive and reproduce but some don’t
 Which moth has a better chance surviving?
 Moth A or Moth B (circle one)
A
B

7. Natural Selection Rests on 4 Elements:
 Which moth has a better chance surviving?
 Moth __ is better ___ for its environment
because it is well ___________ blending into
its background
A
B

8. Natural Selection Rests on 4 Elements:
 Which moth has a better chance surviving?
 Moth B is better fit for its environment
because it is well camouflaged blending into
its background
A
B

9. Natural Selection Rests on 4 Elements:
Which buck has a better chance of survival?
Buck A or Buck B (circle one)
A B

10. Natural Selection Rests on 4 Elements:
Which buck has a better chance of survival?
Buck __ is better ___ for its environment because
it has ______ antlers, therefore a better _______.
A B

11. Natural Selection Rests on 4 Elements:
Which buck has a better chance of survival?
Buck A is better fit for its environment because
it has larger antlers, therefore a better fighter.
A B

12. Natural Selection Rests on 4 Elements:
3) ________: Traits of survivors are passed down
to the _________ (children) through genes

13. Natural Selection Rests on 4 Elements:
3) Heredity: Traits of survivors are passed down
to the offspring (children) through genes

14. Natural Selection Rests on 4 Elements:
3) Heredity: Traits of surviving parent plants
are passed down to the offspring of plants.

15. Natural Selection Rests on 4 Elements:
4) Advantageous traits, which help organisms
survive better than organisms with ______ traits
 Weak organism ____ along with their traits
 Strong organisms _____ and traits are passed ___

16. Natural Selection Rests on 4 Elements:
4) Advantageous traits, which help organisms
survive better than organisms with weaker traits
 Weak organism die along with their traits
 Strong organisms survive and traits are passed on

17. Natural Selection Rests on 4 Elements:
 _________ous ______
The taller giraffe has an ____________ over the
shorter giraffes
 Have easier access
to _____ source
 Shorter giraffes will
eventually ___ out
 Taller giraffes will survive,
________, and out______
the short giraffes.

18. Natural Selection Rests on 4 Elements:
 Advantageous traits
The taller giraffe has an advantage over the
shorter giraffes
 Have easier access
to food source
 Shorter giraffes will
eventually die out
 Taller giraffes will survive,
reproduce, and outnumber
the short giraffes.

19. Examples of Natural Selection:
The Evolution of The Polar Bear
Our story begins with the Polar Bear’s
closest living relative – the Brown Bear

20. The Evolution of The Polar Bear
Around 300,000 years ago a small group of Brown
Bears became reproductively isolated
(separated) from the rest of the population

21. The Evolution of The Polar Bear
This small population
of Brown Bears were
able to survive and
reproduce living in
the Arctic Tundra.
After MANY
generations, a
genetic mutation
occurred . . .

22. The Evolution of The Polar Bear
Because of the genetic mutation, a litter of
Brown Bears were born with white fur.

23. The Evolution of The Polar Bear
How do you think the white fur color affected these
bears chances of surviving long enough to have
cubs (baby bears) of their own?
A.) Brown fur color will survive
better because they existed first
B.) White fur color will survive
better because they’re better
insolated
C.) White fur color will survive
better because they’re
camouflaged in the arctic
D.) White fur color will die out
faster because they stand out in
the arctic

24. The Evolution of The Polar Bear
Which answer choices do eliminate first because
they are the most obviously incorrect?
(cross out two) A / B / C / D
A.) Brown fur color will survive
better because they existed first
B.) White fur color will survive
better because they’re better
insolated
C.) White fur color will survive
better because they’re
camouflaged in the arctic
D.) White fur color will die out
faster because they stand out in
the arctic

25. The Evolution of The Polar Bear
Which answer choices do eliminate first because
they are the most obviously incorrect?
(cross out two) A / B / C / D
A.) Brown fur color will survive
better because they existed first
B.) White fur color will survive
better because they’re better
insolated
C.) White fur color will survive
better because they’re
camouflaged in the arctic
D.) White fur color will die out
faster because they stand out in
the arctic

26. The Evolution of The Polar Bear
This leaves 2 answer choices. Which one is
incorrect and why?
B.) White fur color will survive
better because they’re better
insolated
C.) White fur color will survive
better because they’re
camouflaged in the arctic

27. The Evolution of The Polar Bear
Which one is incorrect and why?
B.) White fur color will survive
better because they’re better
insolated
C.) White fur color will survive
better because they’re
camouflaged in the arctic
B, because insolation traps heat and would make the
bear warmer. Fur color does not change how warm the
bear is.

28. The Evolution of The Polar Bear
How do you think the white fur color affected these
bears chances of surviving long enough to have
cubs (baby bears) of their own?
A.) Brown fur color will survive
better because they existed first
B.) White fur color will survive
better because they’re better
insolated
C.) White fur color will survive
better because they’re
camouflaged in the arctic
D.) White fur color will die out
faster because they stand out in
the arctic

29. REMEMBER: Natural Selection Rests on 4 Elements:
1) There is variation (differences) in the
traits of individuals within a population

30. 2) There is difference in survival
 some survive and reproduce, some don’t
REMEMBER: Natural Selection Rests on 4 Elements:

31. 2) There is difference in survival
 some survive and reproduce, some don’t
REMEMBER: Natural Selection Rests on 4 Elements:
X
X
X
X

32. 3) Heredity: Traits of survivors are passed down
to the offspring (children) through genes
REMEMBER: Natural Selection Rests on 4 Premises:

33. 4) Advantageous traits, which help
organisms survive more than organisms
with weaker traits
REMEMBER: Natural Selection Rests on 4 Premises:
X
X
X
X

35. X X
X
X
X

37. X
X
X
X
X

39. X
X
X
X
X

41. X
X
X
X
X

43. X
X
X
X
X

45. What Happened?

46. Through Reproductive Isolation
(Separation) and Natural Selection . . .
One Species Evolved Into Another
New Species By Adapting To Its New
Environment

47. White moths lay many eggs, which develop
into caterpillars and then adults

48. A moth might be born with a variation that
makes it brown in color

49. Predators are able to find white moths more
easily than brown ones. The brown moths
survive to reproduce, while many white moths
do not.

50. Eventually, moths with brown coloration
make up a larger part of the moth population
than white moths.