The human body is a remarkable product of millions of years of gradual change, shaped by environment, movement, and survival. Many of the physical abilities we rely on every day are the result of adaptations that occurred long before modern life existed. What makes human anatomy especially fascinating is that these changes often happen so slowly that we rarely notice them in our own bodies.
Despite advances in technology and lifestyle, the human body remains very similar to that of people who lived tens of thousands of years ago. While the world around us has transformed rapidly, evolution works at a much slower pace. As a result, some physical features that were once essential for survival are now less necessary. Over time, these structures may become reduced, vary between individuals, or disappear entirely without causing harm.
One example of this can be found in the wrist. A muscle tendon called the palmaris longus plays an important role in animals that rely heavily on their forearms, such as primates that climb or swing through trees. This muscle helps with grip strength and flexibility. As humans adapted to life on the ground and no longer depended on forearm-driven movement, the tendon became less important.
Today, the palmaris longus tendon is missing in a significant number of people. You can check for it by resting your arm palm-up, touching your thumb to your pinky, and gently lifting your hand. A thin band may appear at the wrist. If it doesn’t, it simply reflects natural variation. This small difference doesn’t affect strength or health. Instead, it offers a quiet reminder that evolution is still at work—subtle, ongoing, and visible in our own bodies.
