You're gonna have to give us a picture to support your question..
To show the different levels of classification and divide among species, and different organisms on planet Earth. It also creates a universal "language" for scientists around the world when referring to organisms (cougar & puma are the same animals; different name)
Example: The American Alligator and the Chinese Alligator (look it up!) are in the same family and genus, but are not the same species.
The answer is external stimulus
Scientific modeling is a scientific activity, the aim of which is also to make something a particular part or feature of the word easier to recognize, define, quantify, visualize, or even simulate by referencing it to an existing and usually commonly accepted knowledge.