II - Construction of the phylogenetic tree
General principle : you will progressively add each character on your cladogram while following three fundamental rules:
1- The cladogram must present the distribution of derived character states.
2- Species that share the same derived character states (=create monophyletic groups) must be grouped together.
When several solutions are possible, you must choose the one that implies the fewer number of steps or transformations (=use the principle of parsimony).
Une fois ces règles connues, vous pouvez commencer.
Step 1. The first hypothetical cladogram (with no resolution) is the following:
Cladogram 1.