Evidence of Evolution Inquiry Lab
Unit 2 – Natural Selection, Evolution and Change Over Time
Name:_______________________________
Lab Partners: _________________________
Objectives: Analyze the various types of evidence that supports the theory of evolution.
Procedure: Evolution is an accepted theory in the scientific world. Evidence of evolution comes from many different
sources and many different fields. Through this lab, you will examine six different stations which hold some of the
strongest arguments for evolution.
Station 1: Comparative Anatomy – Homologous Structures: Mammalian Forelimbs
Directions:
Color each
Mammalian
structure with
one color.
Match one
color to each
section of the
forelimb.
Color key:
Scapula: Red
Ulna: Green
Metacarpals:
Purple
Humerus:
Orange
Carpals: Blue
Phalanges:
Black
Radius:
Yellow
Station 2: Oh deer, a Skeletal Mystery!
Key terms:
** Homologous structures: anatomical structures with similar physical form.
** Analogous structures: anatomical structures with similar functions.
1. Compare the bones of the mystery animal on the
table with the human skeleton.
2. Try to find and identify the homologous structures
below:
□ Cranium
□ Vertebrae
□ Humerus
□ Phalanges
Metacarpals
Ribs
Mandible
Femur
3. Fill out the venn diagram with structures that are the
same, alike and different between these two
organisms.
Same
Alike
Different
4. What do these homologous structures tell you about how these two organisms might be related?
5. Are any of these structures analogous?
6. What kind of animal do you think this is?
Station 3: Gimme a hand! (But don’t Gimme a Break!)
A hand is a prehensile, multi-fingered extremity located at the end of an arm or forelimb of primates
such as humans, chimpanzees, monkeys and lemurs. Natural selection has created many variations of hands.
Different environments require different hand abilities. Although not all animals have hands, many have
homologous structures to hands that have evolved.
1. Build a primate hand. Consider the form to function. What does this form of hand allow the animal
to do? Sketch the hand below.
2. Look at the pictures below of the differing homologous structures of hands. Relate the form to
function for each structure.
Human: _____________________________________________________________________________
Horse: ______________________________________________________________________________
Bird: ________________________________________________________________________________
Bat: ________________________________________________________________________________
Seal: _______________________________________________________________________________
Turtle: ______________________________________________________________________________
3. Build your own hand and draw it below! Relate form to function. How would it be useful?
__________________________________________
__________________________________________
__________________________________________
4. Explain why homologous structures provide supportive evidence for the theory of evolution?
____________________________________________________________________________________
____________________________________________________________________________________
____________________________________________________________________________________
Station 4: Biochemical Phylogeny
Read the background information on Biochemical Evidence for Evolution. Take special note of the importance of
embryology as evidence of evolutionary relationships.
1. Follow the instructions on the sheet and fill out the table below:
Key:
+++
++
+
-
Heavy Agglutination (immediate, strong reaction)
Medium Agglutination (Clotting definite, may take a few moments to form)
Slight Agglutination (Reaction weak, takes some time to form a few crystals)
No Reaction
Organism:
1
Human
Cow
Chimpanzee
Frog
Monkey
2
3
4
5
6
7
8
2. Create a phylogeny tree
An evolutionary tree can be created from the results in the data table. An evolutionary tree is a classification system
showing how different organisms are related. At the bottom of the tree are the ancestors, and each branch shows
where the new species separate from the ancestral line. The animal on the data table with the least agglutination
reaction to the Human Antiserum has the least relationship to humans and would be the farthest away from them on
the tree. The greater the number of dilutions the animal’s serum reacts to, the more closely related it is to human, and
the higher it will branch off on the tree.
Phylogenetic Tree:
Why would this test be more accurate than other types of comparisons? A fly and a bird both fly by means
of their wings. Are they closely related?
__________________________________________________________________________________________
__________________________________________________________________________________________
__________________________________________________________________________________________
__________________________________________________________________________________________
__________________________________________________________________________________________
Station 5: Counting Cytocrome C
On the surface, mushrooms and monkeys don’t seem to have much in common. But at the genetic level, these
two organisms aren’t so different after all. Monkeys, mushrooms, and just about all other living creatures have a gene
that codes for a protein called Cytochrome C, which plays a central role in releasing energy from food. Genes and
proteins that govern such basic survival functions tend to be shared by many porganisms, making them an ideal tool for
scientists who want to learn more about relationships among species.
Analyze the Cytochrome C chart. The chart contains the amino acid sequence for Cytochrome C from many
different organisms. Refer to the chart and your knowledge to answer the following questions:
1. What are some of the criteria scientists might use to determine how closely related, in evolutionary time,
two organisms are?
________________________________________________________________________________________
________________________________________________________________________________________
________________________________________________________________________________________
2. What are some of the similarities and differences between humans and each of the organisms listed in the
chart? Consider features that humans share with each organism, as well as ways in which humans differ
from each one.
Similarities:_______________________________________________________________________________
________________________________________________________________________________________
________________________________________________________________________________________
Differences:_______________________________________________________________________________
________________________________________________________________________________________
________________________________________________________________________________________
3. Compare the Cytochrome C amino acid sequence in humans to each of the organisms below. Count the
amount of amino acids that differ from the human sequence and complete the chart:
Organism
Number of Amino Acid Differences
Tuna
Gray Whale
Snapping Turtle
Rhesus Monkey
Chicken/Turkey
Neurospora (a type of bread mold)
4. Which organism are humans most closely related to? ____________________________________________
5. Which organisms are humans most distantly related to?__________________________________________
6. Explain your reasoning: ____________________________________________________________________
________________________________________________________________________________________
7. Explain how amino acid sequence data can help scientists infer patterns of evolutionary relationships
between species. (Hint: Think about the amount of similarity…)
________________________________________________________________________________________
________________________________________________________________________________________
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Station 6: Fossil Cladogram
A phylogenetic tree is a branching diagram showing the inferred evolutionary relationships among
various biological species. Phylogenetic trees measure degrees of similarity. A cladogram is a diagram used to
show ancestral relations between organisms. Cladograms trace the sharing of derived characteristics (or
characteristics DIFFERENT from the ancestral form).
For Part A, create a phylogenetic tree using the diagram below. Next, in Part B, find the bag of pictures
of organisms. Place the organisms in order of the most ancestral organism to the youngest organism. Once
you have them in order, create a cladogram in the space provided.
A. Phylogenetic Tree:
B. Cladogram: