Question

Why did scientist use a classification systems for all living organisms?

Answer 1

The person above answered your question! :)

Answer 2

So that scientists all over the world know exactly what organism is being discussed or investigated Classification of organisms is important because it greatly expands researchers' ability to make educated guesses about particular species. For instance, in many cases, a particular organism may be both difficult to study and also threatened or endangered, or even human and ethically incapable of being experimented upon. However, a related organism may be quite similar to the species of interest, yet not threatened or endangered and without ethical concerns. I see this implementation of classification in the field of herpetology all the time, but it is true across the board in biology