OBJECTIVES Today you will be able to Explain the process of evolution by natural selection Explain adaptation What exactly is evolution in THIS class Evolution a change in the GENETIC ID: 489445
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Slide1
Natural Selection and AdaptationsSlide2
OBJECTIVES
Today, you will be able to…
Explain the process of evolution by natural selection
Explain adaptationSlide3
What exactly is “evolution” in THIS class?
Evolution
- a change in the
GENETIC
characteristics of population from one generation to the next
“Change over time”NOT “Humans evolved from monkeys” Slide4
How does Evolution occur?
Through Natural selection….
That is why it is called “The theory of Evolution by Natural Selection”Slide5
Natural Selection
Process by which individuals that are better suited to their environment
survive
and reproduce most successfully
“survival of
the fittest”Slide6
Example of Natural Selection
Peppered Moth
Before
the Industrial revolution
, the peppered moth in New England was a light gray color and blended in with the lichens that covered trees.
BEFORE
AFTER
After
the start of the industrial revolution, the air was much more
polluted
.
This caused the lichens to die off.
This cause the dark peppered moths to increase in population. Slide7Slide8
How does this happen?
Did the moths magically change colors? Slide9
This is how it happened…
The moth
DID NOT
magically change colors.
The light colored moths did not
blend in with the trees (because they had no lichens).The light colored moths were easily eaten by birds. The dark moths were now better
camouflaged
.
The dark moths were better suited for their environment and were able to survive, reproduce, and increase in population size.Slide10
Quantitatively (Numbers)Slide11
ADAPTATIONSSlide12
What is an “adaptation”
Think about the word “adapt”
Adaptation-
inherited
(mutations) characteristics that increase an organism’s chances for survival.
Examples:
Bird Beaks
Mimicry
Camouflage
Hibernation
MigrationSlide13
Ex: Darwin’s Finches
Charles Darwin-(1800s) a naturalist who developed the theory of
Evolution
via
Natural Selection
.He observed finches on the Galapagos Islands (as well as many other animals)
Through observation, he developed the idea that things
change overtime
and become better suited for their
environment
.
Finches
- lived on different islands; he noticed their beak size was determined by which food source was available Slide14
Darwin’s Finches-What do you think they eat? Slide15
What type of food does this bird eat? Slide16
Examples of AdaptationsSlide17
MimicrySlide18
CamouflageSlide19
What’s the difference?
Mimicry
- when
an animal looks like something else that is meant to be seen (not hidden
)
Camouflage- hides an animal (or something else). If an animal matches its background, it is harder to see.