... Group

Figure 3 is only available in electronic form at http://www.edpsciences.org

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... characters

In cladistics, a character is a trait, a descriptor, an observable, or a property, that can be given at least two states characterizing the evolutionary stages of the object for that character.

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... scenario''

This is not to be confused with the hierarchical organisation of galaxy diversity dealt with in this paper.

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... value "?''

Tables are available on http://hal.ccsd.cnrs/aut/fraix-burnet

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