One selective theme may have a great number of morphological correlates, and ecological and environmental implications. All these implications would appear in the scenario, making it rich and complex, capable of extensive testing, and of great explanatory power, in spite of its underlying parsimony. Clearly the concept of a scenario is more open to mismanagement than a cladogram. Loosely-formed scenarios are not useful. Well constructed scenarios can give a depth of interpretation that no cladogram or tree would ever attempt.
Scenarios are ambitious hypotheses.
It is perhaps more a matter of taste whether one attempts the difficult task of forming a powerful scenario, or tries the simpler approach of cladistic analysis. We present here a scenario. It is a hypothesis which relates the evolution of feathers, of birds, and of flight in birds, to one selective theme of display and intraspecific threat and combat. We present this scenario even though there is no universal agreement on the phylogeny of the transition, in the hope that it will shed light on that phylogenetic question. The only good evidence is the feathers of Archaeopteryx and the possible feather fossil Praeornis .