© 2007 ENSI (Evolution & the Nature of Science Institutes) www.indiana.edu/~ensiweb
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A Mini-Lesson


What did T. rex
taste like?

Online Tutorial at
The UC Museum of Paleontology





The module begins by introducing the three domains of life: bacteria, archaea and eukaryotes, and explains that all living things share a common ancestor. By understanding this single unifying concept, students are able to understand the evolutionary history and relationships of all living things. Students are introduced to the process of illustrating evolutionary relationships with branching diagrams called cladograms. Students learn that once a cladogram has been constructed for a group of organisms, it can be used to answer all kinds of interesting questions based on the shared inherited features of those organisms.


* All living things are related by common ancestry.
* Branching diagrams, called cladograms, are used to illustrate evolutionary relationships.
* Cladograms are based on shared, inherited features.
* Cladograms refine our ability to understand and interpret evolutionary history.


 See Teacher Area (on UCMP lesson site):
Teacher Start > Getting Started [see, in column on left:] > Classroom Tools >
Lesson Plans, or Handouts, or Assessment Materials (Pre/Post tests).

For grades 7-12

Time: 1-4 class periods, depending on reading skills. Could be done as an online homework assignment.


Handouts provided in Teacher Area (on UCMP lesson site)


See Teacher Area (on UCMP lesson site:

This excellent online tutorial introduces students to the family tree and lineage concepts, and extends this to the tree of all life. It takes students through the concepts of common ancestry, shared traits, unique traits, and cladograms (reading, making cladograms, adding new organisms to a cladogram, and making inferences about new organisms).


This lesson would provide an excellent introduction to classification, taking students from the familiar of family trees to the phylogenies of the living world, and the evolutionary implications of that tree. Basic concepts of cladograms are introduced to transition from classification to introduction to evolution.

ENSI Lesson: Making Cladograms
ENSI Lesson: Molecular Biology & Phylogeny (Cytochrome-c)
ENSI Lesson: Why Cladistics?
ENSI Lesson: What is a Zebra?
ENSI Lesson: Nuts & Bolts Classification
ENSI Lesson: Cladistics is a Zip...Baggie


Some of the ideas in this lesson may have been adapted from earlier, unacknowledged sources without our knowledge. If the reader believes this to be the case, please let us know, and appropriate corrections will be made. Thanks.

1. Original Source: UCMP:

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