When we speak of evidence-based practice, many people understand this to mean that therapies or treatments have been proven in well-conducted research.

There is, however, another key type of evidence: the knowledge that comes from the basic sciences, from direct observation.

It is this type of evidence that is core to medical training — from the fine detail of the anatomy and the function of renal tubules and the anterior pituitary to the generation of cardiac action potentials and the role of myelin in nerve conduction.

The advent of technology has allowed us to investigate phenomena beyond the reach of our human senses.