Around the year 1487, Leonardo da Vinci sketched what would become one of the most famous illustrations in the world. In it, a perfectly drawn circle sits atop a square. Perfectly framed within those shapes, with arms and legs outstretched in two different orientations, is a curly-haired, slightly frowning, and very naked man now commonly known as “Vitruvian Man.”
Perhaps no piece of art illustrates the beauty of the human body better than Vitruvian Man. Leonardo obsessed over the perfect proportionality of the human body. He pored over the calculations of the Roman architect Vitruvius, who had labored in the 1st century B.C. to describe the beauty of human proportions. In Book III of his treatise De Architectura, Vitruvius wrote:
For if a man be placed flat on his back, with his hands and feet extended, and a pair of compasses centered at his navel, the fingers and toes of his two hands and feet will touch the circumference of a circle described therefrom. And just as the human body yields a circular outline, so too a square figure may be found from it.
Depicting the human form in this way expressed Leonardo’s belief that humankind represented a microcosm of the universe. Fitting within a circle, humans were a reflection of the celestial. Fitting within a square, humans were also a reflection of the Earth. By inhabiting both shapes, symbolizing different aspects of the universe, humans could bridge the gap between the terrestrial and the divine. As Leonardo wrote in a notebook entry dated to around 1492:
By the ancients man has been called the world in miniature; and certainly this name is well bestowed, because, inasmuch as man is composed of earth, water, air and fire, his body resembles that of the earth.
But there’s a bump in the story. In 2011, Hutan Ashrafian, a lecturer of surgery at Imperial College London, noticed an odd thing about Vitruvian Man. You can be forgiven for not gazing much at Vitruvian Man's package. But not everyone has been so modest, and while looking at Leonardo's illustration, Ashrafian noticed an odd bulge near Vitruvian Man's bulge. This protuberance, slightly above the left side of his groin, looks exactly like a medical problem that plagues about 30 percent of men and 3 percent of women in their lifetimes: an inguinal hernia.
Throughout history, anatomical illustrations have been made using the recently deceased as models, and many of Leonardo's sketches were no exception. Ashrafian says that the man who served as Leonardo’s model for his illustration of human perfection probably had a hernia. If the model was a corpse, the hernia may have been what killed him. If he was a live model, he may ultimately have died from its complications. Other experts agree with Ashrafian, including Jeffrey Young, director at the University of Virginia’s Trauma Center, and Michael Rosen, director of the Comprehensive Hernia Center at University Hospitals Case Medical Center. “If it isn’t a hernia,” says Rosen, “then I really have no idea what it would be.”
The possibility that Vitruvian Man had a hernia is just that, a possibility. “The cool thing with art is it is all in the eye of the beholder,” says Peter Hallowell, director of bariatric surgery at the University of Virginia. If you squint, tilt your head, and look closely at his groin, you might be able to see what the fuss is about. But if you'll indulge me, the significance of Vitruvian Man now becomes all the more profound. It illustrates not just Renaissance ideas of our place in the universe, but it also takes us down a labyrinthine path deep into humans' evolutionary history.
Humans, along with killer whales, deer, and pangolins, are mammals. Our fuzzy, milk-producing lineage evolved about 225 million years ago from reptilian ancestors. For reasons that remain obscure, male mammals usually have their man-parts swinging out in the breeze instead of snuggled comfortably within their bodies.
As a male mammalian fetus develops, his testicles start near the kidneys, and over the course of several weeks take a meandering trip through the inguinal canals before finally being pushed through the abdominal wall to their final resting spot in the scrotum. Females’ reproductive organ development is slightly less complicated, but also involves a passage through the inguinal canals.
Because this process compromises our lower abdominal tissue, our intestines have only a flimsy tissue layer supporting them inside of our body cavity. This isn’t much of a problem for most mammals because they get around on four legs, with their bodies positioned in such a way that the stomach muscles support the weight of the intestines.
But in the human lineage, which has been walking upright for a little longer than 4 million years, the weak layers of lower abdominal wall tissue must bear the brunt of our intestinal weight. When a bit of intestine bulges through a thin layer of lower abdominal tissue, a hernia is born.