While magnificent, the human body is an evolutionary compromise, not a flawless design. We suffer from "evolutionary baggage."

is the largest organ of the human body, covering about 22 square feet and weighing 8–10 pounds. It is a sensory sheet packed with 2.8 million pain fibers, 500,000 touch receptors, and 200,000 temperature sensors. It also synthesizes Vitamin D when exposed to sunlight and acts as a waterproof barrier.