The trap does not work until all the parts were there. The system itself doesn't work until you fit all of them together.

As can be seen even by this limited number of examples proteins carry out amazingly diverse functions.

It was a shock to people of the nineteenth century when they discovered, from observations science had made, that many features of the biological world could be ascribed to the elegant principle of natural selection.

If you take away a rock from a pile of rocks you haven't changed much. It's still a heap of rocks - just a rock or two smaller. Take away a component from the mousetrap and it isn't a mousetrap any more.

In the 19th century the anatomy of the eye was known in great detail and the sophisticated mechanisms it employs to deliver an accurate picture of the outside world astounded everyone who was familiar with them.

Proteins are the machinery of living tissue that builds the structures and carries out the chemical reactions necessary for life.

In order to say that some function is understood, every relevant step in the process must be elucidated.