From an expert in pulmonary medicine, the story of our extraordinary lungs, the organ that both explains our origins and holds the keys to our future as a species We take an average of 7.5 million breaths a year and some 600 million in our lifetime, and what goes on in our body each time oxygen is taken in and carbon dioxide expelled is nothing short of miraculous. “Our lungs are the lynchpin between our bodies and the outside world,” writes Dr. Michael Stephen. And yet, we take our lungs for...