tree-logo.gif (7741 bytes) Plant Taxonomy (BIOL308)  -  Stephen G. Saupe, Ph.D.; Biology Department, College of St. Benedict/St. John's University, Collegeville, MN 56321;;

Cladistics Exercise

The following data matrix lists the characters and character states for three hypothetical taxa (A, B, C) that form a monophyletic group.  Create a cladistic classification of these taxa.

Characters and character states for three hypothetical taxa
Taxon Character
A (Petals) B (Petal Color) C (Gynoecium) D (Ovary position) E (Carpel number) F (stamens) G (fruit) H (leaf)
Taxon 1 connate blue syncarpous inferior 5 numerous achene alternate
Taxon 2 free red syncarpous inferior 5 10 achene alternate
Taxon 3 free yellow apocarpous superior 2 numerous drupe opposite
Outgroup free yellow apocarpous superior 2 10 drupe alternate
  1. Draw the four possible cladograms that include the three taxa.  Include the outgroup for each.
  2. Assume that the outgroup exhibits only the pleisomorphic condition for each character.  Then, plot each character on the three.  Use a bar (-) on the branch of the cladogram to represent clades that possess the apomorphic condition.
  3. Determine which cladogram is best (Principle of Parsimony).

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Last updated:  08/20/2007 / � Copyright by SG Saupe