Evolutionary classification has its own problems:

• Evolutionary taxonomists classify by homologies but do not distinguish between ancestral and shared derived homologies. Shared derived homologies cannot (if correctly identified) contradict one another; but different ancestral homologies can end up distributed in contradictory groupings.

An evolutionary classification will therefore only be objective insofar as shared derived homologies were used to construct it. If it contains shared ancestral homologies the classification will be less objective: an evolutionary classification is only objective insofar as it is cladistic.

• Classifications that mix more than one type of information are less informative than classifications that represent only a single property. The problem with evolutionary classification is that it is constructed with both phenetic and phylogenetic information: if you are given the classification, you do not know which groups are phenetic and which phylogenetic.

Classification by a pure system does not have this problem.