By having a large number of comparative, more reliable characteristics - anatomical, embryological, functional, genetic, behavioral, etc. - Biologists interested in the classification of living beings were able to make more consistent assumptions about the evolution of large groups.
Influenced by the work of Wili Hennig - a German scientist, expert in insects - came to present the characteristics in cladograms.
In this type of diagram, a line is used whose point of origin - the root - symbolizes a probable ancestral group (or species). Decade at the a branch, which leads to one or more terminal groups. With cladograms a comparison can be made between the primitive characteristics - which existed in ancestral groups - and the derived ones - shared by succeeding groups.
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