Human left lungs are approximately ten percent smaller than their right counterparts and only have two lobes instead of three, an evolutionary concession made entirely to accommodate the heart.

A closer look

Human left lungs are approximately ten percent smaller than their right counterparts and only have two lobes instead of three, an evolutionary concession made entirely to accommodate the heart. Your cardiovascular engine is such a biological diva that it essentially stole real estate from your respiratory system just so it could sit slightly off-center in your chest cavity. We walk around thinking our bodies are perfectly symmetrical masterpieces of intelligent design, but inside it is basically a cramped studio apartment where the organs are fighting over square footage. The right lung has to do overtime breathing in the smog-filled air of modern cities just because the heart demanded a corner office with extra legroom to pump blood through our stress-riddled veins