Name __________________________________ per ____ date _______
DUE: _________
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Constructing Evolutionary Relationships Using Genetics
DIRECTIONS:
1. Find the human, rhesus monkey, kangaroo, snapping turtle,
bullfrog, and tuna on the "Amino Acid Sequence Differences in
Cytochrome-C Proteins from 20 Different Species" chart provided
(last page). Highlight their entire protein sequences (using
alternating highlighter colors if possible). NOTE: there are two rows
for each organism, part at the top of page AND the part on the
bottom of the page.
2. Compare the human amino acid sequence with each of these five animals (rhesus monkey, kangaroo, snapping
turtle, bullfrog, and tuna). Do this by counting the number of times an amino acid in that animal’s protein is
different from the same amino acid position of the human sequence. Write that information in the table below.
Data Table: DNA Evidence for Evolutionary Relationships
# of amino acid
differences in
Organisms compared
Cytochrome-C
protein
Rhesus Monkey vs. human
Kangaroo vs. human
Snapping Turtle vs. human
Bull Frog vs. human
Tuna Fish vs. human
#1 Based on genetics
3. Record the total number of
amino acid differences between
humans and each animal on the
cladogram #1. Write your
answer in the hexagon below
the arrow pointing to the name
of that animal.
4. Compare to cladogram #2.
Does the cladogram organized
by genetic information agree
with the cladogram organized
by anatomical features? Does
this make sense? Why or why
not?
#2 Cladogram with derived characters
Name __________________________________ per ____ date _______
DUE: _________
2
5. Which is a better method of finding evolutionary relationships, using physical features in common or amino acid
sequences in common? Make a claim to answer this question, supported with evidence and reasoning.
Claim:
Evidence:
Reasoning:
6. If comparing genetic information, the physical similarities, and the fossil record all support the same model of
evolutionary relationships, can we be confident that this model of evolution is accurate? Why or why not?
9. Next, you will construct a cladogram of the phylogeny between humans, dogs, wheat, and fungus (baker’s yeast). First,
make some predictions.
a) Which organism do you predict is most closely related to humans? __________________
b) Which organism do you predict is least related to humans- wheat or fungus? _________________
a. WHY??
c) Of all 4 organisms (humans, dogs, wheat, fungus), predict which two you think most recently evolved from a
common ancestor (are most related)? _____________ and ______________
a. What makes you think that?
d) Now, highlight the differences on the amino acid chart from both rows of amino acid data to find how many
differences each organism has compared to humans. Fill in the table. Then draw the cladogram.
# amino acid
differences
compared to
humans
e)
Draw the cladogram:
dogs
wheat
fungus
10. Next, use the amino acid data to answer your own evolutionary relationships question. Look at the organisms on the
chart that we haven’t used yet. What do you want to know about which ones are most related?? Or not??
a) Pick any 3 organisms on the chart not yet used and write a question here that you can answer by comparing their
amino acid data:
My question: ___________________________________________________________________________
b) Pick one to start with and then compare it to the two others. Draw a chart below, then a cladogram.
c) Finally, write the answer you found to your question below the cladogram.
Name __________________________________ per ____ date _______
DUE: _________
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