Core Concept: Why Do We Classify Life?

The Simple Idea: Imagine walking into the world's largest library with 8.7 million books and no catalogue system — impossible to find anything. Biological classification is that catalogue system for life. R.H. Whittaker in 1969 said: "Let us sort all living things into 5 big shelves based on what they look like inside (cell type), how they get food (nutrition), and how they're built (body plan)."