Name: _________________________________________ Date: _____________________ Hour:_________
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.
Fill out the following character matrix. Mark an “X” if an organism has the trait.
Cells
Legs
Antenna
Wings
2 sets of wings
Worm
Spider
Carpenter Ant
House fly
Dragonfly
In the box below, create a cladogram based off your matrix.
(above)
1. Start with a timeline: oldest organisms on the bottom left, newest on the top right.
2. use your derived characters to show the appearance of new species carrying that trait in your timeline.
3. Remeber: your derived characters are cummulative!
4. Show each new species branching off to the left and up in your timeline. Name each species.
READ!
x
x x
x x x
x x x x
x x x x x
JUNEBUGS X X X X X X
shell over
wings
