Yes, classification system is still evolving together with our knowledge.
But, before changing the name (e.g. of a species) it is important to collect and gather a wealth of information in order to support that change. Classification system is still evolving. The reasons for the changes are DNA analyzes. It is the new way for discovering relation between organisms and put them in the right context (classification used to be based on morphological characteristics).
Change in classification can be shown in an example of fungi. In the 90s fungi classification included only phyla Chytridiomycota and Zygomycota. Now theyhave been classified mainly on the basis of characteristics of their sexual reproductive structures. So, there are 7 phyla now: Microsporidia, Chytridiomycota, Blastocladiomycota, Neocallimastigomycota, Glomeromycota, Ascomycota, and Basidiomycota
Perhaps the answer is "physical characteristics". I am simply making an educated guess, however I do know early philosophers classified organisms into two groups, Plants and Animals, and identified them based on physical characteristics.
