Transcript Evidence of Evolution

1.
Give one example of
an adaptation and
explain why it is an
adaptation.
2.
Define evolution by
natural selection.
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3. Give an example
of geographic
isolation.
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4. How are
convergent and
divergent evolution
different?
 Catalyst (5 minutes)
 Speciation Beach Ball review (5 minutes)
 Evidence of Evolution (15 minutes)
 ThinkTacToe (20 minutes
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Homework:
 None
 Honors: 9 weeks project due September
30th
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Mastery grades
Office hours tomorrow
Dojo review
Binder quiz this week ;)
Parent teacher conferences on Thursday
What determines which organisms survive
and which do not?
 Do species ever change?
 How do scientists believe all of the species
that exist today were formed?
 What evidence is there to support
evolution?
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Crawlers from The Descent
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Humanoid
Cave-dwelling
Blind
No pigment
Moist skin
Incredible grip/climbing
abilities
 Bat-like ears
 Echolocation
 Carnivorous (raw meat)
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Are the crawlers a valid example of natural
selection?
What are their adaptations?
Are they favorable?
Is it believable?
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Cave dwelling
organisms
(Troglobites)
Instead of
“gaining” favorable
adaptations, they
lose adaptations
they no longer
need.
Divergent evolution
Speciation
Species
Convergent evolution
Geographic isolation
Reproductive isolation
Common ancestor
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SPI 3210.5.3 Recognize the relationships among
environmental change, genetic variation, natural
selection, and the emergence of a new species.
SWBAT identify the various forms of evidence
supporting evolution
 SWBAT explain how homologous structures
demonstrate common ancestry (relatedness) and
support evolutionary theory
 SWBAT identify examples of vestigial structures and
explain how vestigial structures provide evidence
supporting evolution
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Biology
Unit 3
Chapter 15, Section 2

Evolution by natural selection is considered
the best scientific explanation for the
existence and diversity of life
 Scientific= testable & observable
 Keep in mind that science cannot prove or
explain everything, however
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Scientists use many forms of scientific
evidence in support of evolution
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We will focus on 4 forms of evidence
 Fossils
 Homologous structures
 Vestigial structures
 DNA sequencing
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Definition: Structures with similar composition,
placement and form but different functions
 Examples: Human arm, cat leg, horse leg, dolphin
flipper, and bat wing
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How do homologous structures provide
evidence in support of evolution?
 Homologous structures suggest that
organisms evolved from and share a
common ancestor because of their similar
bone structure and placement.
 They have different functions because each
species adapted to different environments
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What about structures with the same function?
Analogous structures are structures that
evolved in unrelated species, but have the
same function in different organisms
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Example: Bird wings vs. insect wings
They are found in unrelated species that only
use them for similar functions.
 These DO NOT provide evidence of evolution
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Mammals and insects both use their legs to
walk. However, their limbs are made of
different types of tissues and these
organisms are not closely related.
These are analogous structures
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Definition: Structures with little or no
known function in one organism but known
to have a significant function in other
organisms
 Examples: Snake pelvis, Kiwi wings, human
appendix
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How do vestigial structures provide
evidence in support of evolution?
 These structures suggest that a species
evolved because they are known to have
important functions in other organisms, so
they likely did in an ancestor of the species
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You must complete at least 5 THINK boxes.
Regular: You must complete one box in each
column. (i.e. 1 from T, 1 from H, 1 from I, etc.)
You may choose ANY boxes in the column.
(Honors: 3 of your boxes must be from the
“N” or “K” columns.)
On your own sheet of paper, write whatever
column and your answer in COMPLETE
SENTENCES
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Honors 9 weeks projects
Office hours
Binder quiz
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ALA #1
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Catalyst: 10 minutes
ActivExpression Review: 10 minutes
Evidence of Evolution, part 2: 10 minutes
Manipulatives: 15 minutes
Homework: Evidence for Evolution
Homework
Unit 3 Study Guide due Monday
Honors 1st 9 weeks projects
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Parent teacher conferences on Thursday
What determines which organisms survive
and which do not?
 Do species ever change?
 How do scientists believe all of the species
that exist today were formed?
 What evidence is there to support
evolution?


SPI 3210.5.3 Recognize the relationships among
environmental change, genetic variation, natural
selection, and the emergence of a new species.
SWBAT identify the various forms of evidence
supporting evolution
 SWBAT explain how homologous structures
demonstrate common ancestry (relatedness) and
support evolutionary theory
 SWBAT identify examples of vestigial structures and
explain how vestigial structures provide evidence
supporting evolution

Biology
Unit 3
Chapter 15, Section 2
 Define evolution.
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Define speciation.
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Octopi are able to change color and
texture to blend in with their
environments. What type of
adaptation is this AND what
environmental factor contributes to
this adaptation?
Male peacocks with the most colorful tail
feathers are most likely to finding a mate.
Female peacocks choose mates based on
the color of their tail feathers. In reality, not
all males have bright, large tails, and this
was especially true a few thousand years
ago. Females are not likely to choose those
males as mates. Predict which tail feathers
the majority of the male peacock
population have today using the four
principles of natural selection.
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Define divergent evolution.
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Rainbow trout spawn
(reproduce) in the spring.
Brown trout spawn in the
fall. These two types of
organisms are not able to
mate and not the same
species. Is this an
example of geographic or
reproductive isolation?
A forest fire causes the permanent separation of a group of
deer from their native population, causing the small group to
interbreed only with one another. Over time, the group
becomes an entirely different species.
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Is this a result of geographic or reproductive
isolation?
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Ducks and platypuses both
have bills and webbed feet.
However, they are not
related. Is this an example of
convergent or divergent
evolution?
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Darwin studied finches on
the Galapagos Islands.
These birds had evolved
different beaks to eat the
different available food on
different islands.
Convergent or divergent
evolution?
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Give an example of two
homologous structures.
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Definition: Preserved
remains or imprints of
organisms that are found
in various levels of the
earth
 Bones, shells, imprints, etc.
 Older fossils are found
deeper in the earth; newer
fossils are found near the
earth’s surface
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How does the fossil record provide evidence of
evolution?
Many fossils are intermediate forms, whose
features show a transition from ancient species to
modern species
 Features are in between those of ancient and modern
organisms
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This suggests that many species of organisms
have gradually changed over time
 Evolution
MODERN
OLDER
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Definition: Comparison of
all of the genes (genome)
found in different species
of organisms
 Example: Human vs.
chimpanzee DNA
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How does DNA sequencing provide
evidence of evolution?
 DNA sequencing shows many similarities in
the genome (all of the genes) of different
species
 Species with higher percentages of their DNA
(genome) in common are thought to be more
closely related and to share a common
ancestor
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Which two species
are most closely
related?
Species
DNA Sequence
Species 1
ACT GGT CCA
Species 2
ACT GGC TCA
Species 1 and 3
Species 3
ACT GTT CCA
Species
ACC GGT CTA
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Which two species are most closely related?
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Species 3 and 4
Species
DNA Sequence
Species 1
CCC GTG ATC TTA
Species 2
CTC GGG ATC TCA
Species 3
CCG TGG ATC TCA
Species 4
CCG TTG ATG TCA
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Which of the following is the best definition of
analogous structures?
A. Structures that evolved in unrelated species but
have the same function
B. Structures with little or no known function in one
species but an important function in other species
C. Structures with similar form and placement but
different functions
D. Structures left behind in various layers of the Earth
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Answer: A.
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Which of the following is the best definition of
homologous structures?
A. Structures that evolved in unrelated species but
have the same function
B. Structures with little or no known function in one
species but an important function in other species
C. Structures with similar form and placement but
different functions
D. Structures left behind in various layers of the Earth
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Answer: C.
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Ostriches have wings even though they do
not fly. What type of structures are the
ostrich wings?
Why do scientists suggest ostriches have
wings?
Answer: Vestigial structures; because they
were used (function) in an ancestor species
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The structures below are similar in form but
have different functions in different species.
What type of structure are they?
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Why are they different?
Answer: Homologous structures; the species
adapted to different environments
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The pictures below show fossils of related
species. The fossil on the right was found
deeper in the earth than the one on the left.
Which species is thought to be older?
Which species is thought to have evolved
more recently?
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Sort the cards into 4 piles—one for
Homologous Structures, one for Analogous
Structures, one for Vestigial Structures, and
one for Fossils
Check your piles with Ms. M when complete
Then begin on your homework
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Read the article “T-Rex as a Scavenger” and
answer the following questions.
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1. What is the difference between a scavenger
and a predator?
2. What was Horner’s evidence for the T-Rex
as a scavenger?
3. What evidence did dePalma and colleagues
provide for T-Rex as an apex predator?
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 Catalyst (15 minutes)
 Evolution Stations (25 minutes)
 Closing (Remainder)
 Homework:
 Study for Unit 3 exam
 Honors: 9 weeks project due
September 30th


Parent teacher conferences tomorrow
Regular: bring your study guide tomorrow
What determines which organisms survive
and which do not?
 Do species ever change?
 How do scientists believe all of the species
that exist today were formed?
 What evidence is there to support
evolution?





Moving desks
How we rotate
Work
Expectations
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Unit 3 exam on Monday
Unit 3 study guide due on Monday
Honors 9 week projects