Making an Evolutionary Tree
You have learned how evolutionary relationships among
living organisms and their ancestors can be displayed on a
branching diagram called an evolutionary tree. In this
activity, you will create an evolutionary tree showing
evolutionary relationships among vertebrates and their
ancestors.
For this activity you will need a large sheet of newsprint or
poster board, markers, pencils, glue, and magazine pictures
of the following animals: shark, trout, frog, lizard, snake,
turtle, crocodile, bird, kangaroo, mouse, and human.What you will do- Use the diagram to the right as a template for your
evolutionary tree. - Use the information in the diagram to place the
organisms listed above at the correct numbers on the
diagram. - Draw your tree on newsprint or poster board. Use a
pencil first, then use markers to add color. - Find pictures of the different vertebrates in magazines or
using the Internet. Cut out your pictures and glue them
on your tree. - Answer the questions below and present your
evolutionary tree to your class for discussion.
Applying your knowledge
a. Mammals evolved from an extinct group of organisms
called therapsids. Where would therapsids be placed on
your diagram (node A, B, or C)?
b. Early reptiles gave rise to all vertebrates except for fish
and amphibians. Where would early reptiles be placed on
your diagram (node A, B, or C)?
c. Sea squirts are chordates but do not have a backbone.
Where would sea squirts be placed on your diagram (node
A, B, or C)?