Name:___________________________________ Date: ________________ Period: _____ Score:______
PART 1: A Phylogeny of Beasties – BACKGROUND
In this exercise, you will reconstruct the evolutionary history of a group of imaginary organisms known
as Beasties. The Beasties are a morphologically diverse group (they all look different). Your analysis will
compare this diversity and use it to help you sort the Beasties by their related characteristics. You will
use the differences and similarities in their characteristics to infer the simplest phylogenetic tree for the
group of Beasties depicted below.
The outgroup taxon (below right) is your standard; its morphology is your starting point for comparisons
with all other Beasties (A – F). The outgroup is only distantly related to the other specimen. Follow the
instructions carefully to help you analyze the Beasties creatures, compare them, and then use that
information to make a phylogenetic tree.
Overview of Requirements:
 Character Analysis (Table 1)– list of characters used to compare specimen and short descriptions
 Comparison Data Table (Table 2) – analysis of the characteristics present in each specimen
 Ranked Data Table (Table 3) – ranking the specimen based on how similar or different they are
from the outgroup
 Phylogenetic Tree (Figure 1) - A tree depicting the simplest estimate of evolutionary
relationships for the Beasties with the characteristics mapped onto the phylogeny
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1. CHARACTER ANALYSIS – Table 1:
a. Examining the specimens above. How many characteristics can you identify?
b. Make a list of these characteristics in the first column of Table 1.
c. For each characteristic, 2 possibilities exist, present or absent. Use a 0 to represent the
absence of a characteristic and a 1 to indicate the presence of a characteristic.
Remember to code any characteristic in your outgroup as 0. Finish Table 1.
2. COMPARISON DATA TABLE – Table 2:
a. List the characteristics you developed in step #1 in the top row of Table 2.
b. Fill in Table 2 with 0s and 1s, indicating the presence or absence of each characteristic
for each specimen.
3. RANKED DATA TABLE – Table 3
a. Do NOT immediately fill in the specimen letters or characteristics as you had in Table 2 –
you will figuring out how to reorder them now!
b. What characteristic do ALL Beasties EXCEPT the outgroup have in common? List this
characteristic as the 1st characteristic in the top row of Table 3.
c. In preparation for determining the simplest tree, the specimen need to be sorted and
ranked by how similar and how different they are from the outgroup. Review Table 2 –
which specimen is most similar to the outgroup (i.e., shares the most characteristics)?
List the organisms’ letter in Table 3 in the row immediately under the outgroup.
d. For that organism, what characteristic differentiates it from the outgroup? List that
characteristic as the 2nd characteristic in the top row.
e. Starting with those specimen that are most similar with the outgroup, continue to
organize and rank the specimen in descending order in Table 3. As you write each
letter, determine which characteristic that makes it unique from the others, and add
that characteristic name to the top row.
f. HINT: when finished, the specimen listed in Table 3 should NOT be in alphabetic order
(A-F) as they were in Table 2. They will now be listed from most to least similar. The
order of your characteristics will now also be different – ranked from most shared to
most unique characteristics.
4. PHYLOGENETIC TREE – Figure 4
Do this in PENCIL first! Then color code.
a. Start with the outgroup as your first branch of the phylogenetic tree.
b. The Beastie most similar to the outgroup will be the next branch of phylogenetic tree.
c. For each new characteristic that is unique to the outgroup, make a new branch of the
phylogenetic tree and write the letter of the specimen there. Construct the entire tree.
d. Color code it! Make a Key to identify a different color for each characteristic listed in
Table 1. For each characteristic, trace any penciled lines with that color to indicate the
presence (1) of that characteristic. Repeat for each characteristic. When finished, the
line leading up to each organism should have a unique “rainbow” pattern of colors.
e. At each branch of the tree where a new characteristic (color) appears, label it as such
(see page 342 & 343 in your textbook for examples of labeling). This spots indicate the
develop of a new characteristic, that each of the following organisms on the same line
will have.
5. CONCLUSION QUESTIONS: answer the questions regarding the beastie phylogeny.
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Name:___________________________________ Date: ________________ Period: _____ Score:______
A Phylogeny of Beasties – DATA SHEET
Table 1. Beastie Characters (REMEMBER – the outgroup will have a “0” for each character!)
Characteristic Name
e.g., Ears
Coding scheme
0: absent (outgroup) 1: present
Table 2. Comparison Data Table
Characteristics
Taxon
Outgroup
A
B
C
D
E
F
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LEAVE THIS PAGE BLANK!!!!
DATA TABLES CANNOT BE COPIED FRONT-TO-BACK!
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Name:___________________________________ Date: ________________ Period: _____ Score:______
Table 3. Ranked Data Table
Characteristics
Taxon
Outgroup
Figure 1. Beastie phylogeny (sketch your phylogenetic tree here, PENCIL 1st, then color code)
COLOR KEY
Characteristic
Color
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Beastie Phylogeny Conclusion Questions
1. What is the most inclusive group in your phylogeny (it should only include 2 species)? What is
the unique characteristic that defines this group?
2. List 3 characteristics that are unique to a particular Beastie. To which Beastie do each of these
belong?
3. Based on your tree, circle only the comparisons listed below that are sister to each other (only 1
branch apart):
C to D
A to C
E to B
(F,A,C )to (D,B)
E to (F,C, A)
E to (D, B, A, C, F)
C to (A,F)
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