PURPOSES OF CLASSIFICATIONS

Use of the scientific method to achieve valid generalizations in biology rests on classifications. If a proposition is empirically known to be true of several organisms, it is normally postulated, as a hypothesis to be tested, that it is true of all members of the smallest taxon to which all the known instances belong. If possible, further instances testing the hypothesis, are sought among the organisms most distantly related to those already known while still within the taxon about which the generalization has been postulated.