To understand how and why organisms function the way they do, and how they interact with one another, we must observe patterns in development and evolution. Think about the scope of the Life Science Content Standards: understanding the cell; molecular basis of heredity; biological evolution; interdependence of organisms, matter, and energy; organization in living systems; and behavior of organisms. Classification is a scientific approach to grouping organisms based on current knowledge gathered from all of these fields.

It is more important to understand how and why classification systems are organized than to memorize each individual level. Classification systems encompass a wide, dynamic body of knowledge that is being modified continually.