Name: Diana Medina
Period: 5
Date: 03/10/2022
Evidence for the Theory of Evolution
(Adapted from: Prentice Hall Laboratory Manual)
NGSSS:
SC.912.L.15.1 Explain the scientific theory of evolution is supported by the fossil record,
comparative anatomy, comparative embryology, biogeography, molecular biology, and
observed evolutionary change. AA (Also addresses: SC.912.N.1.3, SC.912.N.1.6,
SC.912.N.3.1, SC.912.N.3.4)
Background:
Evolution is not just a historical process; it is occurring at this moment. Populations
constantly adapt in response to changes in their environment and thereby accumulate
changes in the genes that are available to the species through its gene pool. In today's
lab you will explore some of the evidence for evolution and will examine a few of the
mechanisms through which evolution acts. In this laboratory you will review some of the
classical examples used as evidence for evolution.
Problem Statement: What are some evidences that support the theory of evolution?
Vocabulary: evolution, fossil, homologous structures, molecular biology, vestigial organ,
comparative biology
Procedures:
1. Read the Station Cards carefully.
2. Follow the instructions.
Observations:
Station 1: Fossil Record
a. Give two similarities between each of the skulls that might lead to the conclusion that these are
all related species.
b. What is the biggest change in skull anatomy that occurred from the dawn horse to the modern
horse?
c. What is the biggest change in leg anatomy that occurred from the dawn horse to the modern
horse?
Station 2: Comparative Embryology
Table 1
Species
Human
Chicken
Rabbit
Tortoise
Salamander
Fish
Table 3
Species
Human
Chicken
Rabbit
Tortoise
Salamander
Fish
Table 2
Embryo
Embryo
Species
Human
Chicken
Rabbit
Tortoise
Salamander
Fish
Embryo
Anatomical Changes From Early to Late Stages
Table 4
Species
List similarities of each embryo to others
Human
Chicken
Rabbit
Tortoise
Salamander
Fish
Explain how the similarities between these embryos are used as evidence of a common
ancestry.
Station 3: Comparative Anatomy (Homologous Structures)
Table 5
Animal
Function of Structure
Human
Whale
Cat
Bat
Bird
Crocodile
Table 6
Animal
Comparison to Human Arm in Form
Whale
Whale has a much shorter and thicker
humerus, radius, and ulna. Much
longer metacarpals. Thumb has been
shortened to a stub.
Cat
Bat
Bird
Crocodile
Comparison to Human Arm in
Function
The whale fin needs to be longer to
help in movement through water.
Thumbs are not necessary as the fins
are not used for grasping.
Station 4: Comparative Anatomy (Analogous Structures)
a. What is the function of these structures?
b. How are they different in form? Give specific differences.
c. Do birds and insects share any structural (elements inside the wing) similarities that would
suggest they are closely related taxonomically?
Station 5: Comparative Anatomy (Vestigial Structures)
a. What is the biggest, most obvious difference between the body structures of these two fish?
b. Assume the two fish came from the same original ancestor. Why might the cave fish have
evolved without eyesight?
c. What kind of sensory adaptation would you hypothesize the cave fish has to allow it to navigate
in a cave, including catching and eating food?
d. How are vestigial structures an example of evidence of evolution?
Table 7 (Vestigial Structures)
Structure
Possible Function
appendix (digests leaves in
koala bears)
Digestion
coccyx (tail bones)
muscles that move ears
Wisdom teeth
Why vestigial?
Do not have a tail
Hear in different directions
(detect predators or prey)
Smaller jaws leaves no room
for wisdom teeth (diet)
Station 6: Biogeography
a. What ecological conditions caused the similarities in the body plan of these animals?
b. How can two species that look very different from each other be more closely related than two
other species that look similar to each other? (i.e. a dolphin and a rat are more closely related
than a dolphin and a shark)
Station 7: Observable Changes
a. What could have originally caused the existence of two forms of the same species of moth?
b. Why is variation among individuals so important to the process of natural selection? What are
the main sources of this variation?
c. What do you think cause the rapid change in the populations of peppered moths from a light to
a dark coloration?
d. The British have instituted pollution controls on factories. What would happen to the moth
populations if the pollution created by the Industrial Revolution were to be reversed?
Station 8: Molecular Biology
Table 8
Animal
Number of Amino Acid
Differences Compared to Human
Cytochrome C
Animal
Horse
Shark
Chicken
Turtle
Tuna
Monkey
Frog
Rabbit
Number of Amino Acid
Differences Compared to
Human Cytochrome C
a. Based on the Cytochrome C data, which organism is most closely related to humans? Why?
b. Do any of the organisms have the same number of differences from human Cytochrome C? In
situations like this, how would you decide which is more closely related to humans?
c. Using the shared molecular similarity data below, place the letter (inside the circle) representing
each species’ molecular difference to a target on the phylogenetic tree.
% divergent from human DNA
Common Primate Ancestor
A
4.3
B
1.8
C
7.0
D
1.7
E
3.3
F
24.6
G
10.8
Analysis:
1. Given the amount of research and evidence available on evolution, why is it classified as a
theory?
2. Charles Darwin published his book On the Origin of Species in 1859. Of the different types of
evidence that you have examined, which do you think he relied upon the most, and why?
3. How can Darwin legitimately argue about the imperfection of the fossil record and then go on to
show how the fossil record can be used to support evolution?
4. How are mass extinctions good evidence in favor of evolution?
5. Why are transitional species, such as the ancestors of modern whales or horses, crucial evidence
for evolution?
6. Fly embryos and frog embryos differ from each other more than frog embryos and ape embryos
do. What does this imply about how these groups may be related?
7. What are the differences between "homologous" organs and "analogous" organs? Find some
examples of your own.
8. The bones of a human arm are very similar to the bones in a bird’s wing and a dolphin’s flipper.
What does this similarity in structure reveal about the ancestry of these animals?
9. Even if a "rudimentary organ" actually has a function about which we observers are unaware
(e.g., if vestigial pelvic bones of a whale may function to support gonads), why would it still
provide excellent evidence in support of evolution by descent?
10. Explain how sequences of amino acids in proteins can be used to reveal relationships among
organisms.
Conclusions:
Explain how each of the following provides evidence for evolution:
 Fossil evidence
 Comparative embryology
 Comparative anatomy
o homologous structures
o analogous structures
o vestigial structures
 Biogeography
 Observable changes
 Molecular biology