Name: ___________________________________________________ Date: ______
H Bio Cladograms
GALLO
Examine the cladogram below and answer the following questions.
1. Which groups X and Y OR X, Y, and Z have the most recent common ancestor?
2. Which species X and Y OR X and Z share a more derived characters?
The cladogram below shows the evolutionary relationships among four groups of plants.
3 Which of the following groups, taken by themselves, do NOT forms a clade?
A. cone-bearing plants’ and flowering plants
B. ferns, cone-bearing plants, and flowering plants
C. mosses and ferns
D. mosses, ferns, cone-bearing plants, and flowering plants
4. Which of the following groups share the most recent common ancestor?
A. cone-bearing plants and flowering plants
B. mosses and ferns
C. mosses and cone-bearing plants
D. ferns and flowering plants
5. Which derived character appeared first during the course of the plants’’ evolution?
A. seeds
B. flowers
C. embryo
D. vascular tissue
1. List the organisms that show multicellularity:
2. List any organisms that lack tissues:
3. List organisms with radial symmetry:
4. What organisms have deuterostomic development?
5. List protostome organisms that have a coelom (Note: deuterostome development replaces protostome
development)
6. Circle the point (i.e. node) on the cladogram that marks the most recent common ancestor of mollusks,
annelids, arthropods, echinoderms and chordates.
CLADOGRAM ANALYSIS
What is a cladogram? It is a diagram that depicts evolutionary relationships among groups. It is based
on PHYLOGENY, which is the study of evolutionary relationships. Sometimes a cladogram is called a phylogenetic
tree (though technically, there are minor differences between the two).
In the past, biologists would group organisms based solely on their physical appearance. Today, with the advances in
genetics and biochemistry, biologists can look more closely at individuals to discover their pattern of evolution, and
group them accordingly - this strategy is called EVOLUTIONARY CLASSIFICATION
CLADISTICS is form of analysis that looks at features of organisms that are considered "innovations", or newer
features that serve some kind of purpose. (Think about what the word "innovation" means in regular language.)
These characteristics appear in later organisms but not earlier ones and are called DERIVED.
CHARACTERS.
PART I - Analyze the Cladogram
Examine the sample cladogram, each letter on the diagram points to a derived character, or something different
(or newer) than what was seen in previous groups. Match the letter to its character. Note: this cladogram was
created for simplicity and understanding, it does not represent the established phylogeny for insects and their
relatives.
1. ______ Wings
2. ______ 6 Legs
3. ______ Segmented Body
4. ______ Double set of wings
5. ______ Cerci (abdominal appendages)
6. ______ Crushing mouthparts
7. ______ Legs
8. ______ Curly Antennae
PART II - Create Your Own Cladogram
To make a cladogram, you must first look at the animals you are studying and establish characteristics that they
share and ones that are unique to each group. For the animals on the table, indicate whether the characteristic is
present or not. Based on that chart, create a cladogram like the one pictured above.
Cells
Slug
Catfish
Frog
Tiger
Human
Backbone Legs Hair
Opposable
Thumbs
DRAWING OF YOUR CLADOGRAM
The table show the number of amino acid differences in the cytochrome c protein
pairs for animal species. Use this information to determine the evolutionary
relationships among these species. Write the name of each species in the correct
blank box in the diagram below.
HORSE
MOTH
SNAKE
WHALE
Number of Amino Acid Differences Between Species
CHICKEN
HORSE
MOTH
11
0
29
29
0
21
18
29
9
5
27
SNAKE
0
18
Venn Diagram Template:
Cladogram: