Our bodies are truly incredible creations, functioning as complex instruments that reflect the wonder of natural evolution. Despite their brilliance, many of us often overlook just how extraordinary our physical forms are. When you pause to consider the bigger picture, it’s astounding to think about the journey we’ve undergone over millions of years.

Human beings have evolved from creatures that were strikingly similar to modern-day chimpanzees into sophisticated beings capable of walking, talking, building intricate societies, and even launching spacecraft into the cosmos. This incredible transformation happened in what feels like a fleeting moment when compared to the vast age of the universe. It’s a testament to the power of evolution and our remarkable adaptability.

What’s even more fascinating is that, in many ways, our bodies have remained largely unchanged over the past twenty thousand years. Although we now live in an environment dramatically different from the one our ancestors inhabited, much of our physical structure still reflects their way of life. Yet, evolution continues, albeit at a pace so gradual that it’s often imperceptible within a single lifetime. Even though we may not notice these changes, they’re happening nonetheless, and they provide a glimpse into the ongoing story of humanity’s development.

One small but intriguing example of this ongoing evolution lies in a seemingly simple tendon located in your wrist. This tendon connects us to an ancient muscle called the palmaris longus, a feature that has become increasingly rare in the human population. Understanding its significance helps us see how evolution shapes us, even in ways we might not expect.

The Palmaris Longus Tendon and Its Evolutionary Role

The palmaris longus tendon is tied to an ancient muscle that played an important role for many animals. For species that rely heavily on their forearms for mobility—such as lemurs and monkeys—this muscle provides critical support for their movement. It helps them swing from branch to branch and perform other tasks essential to their survival in treetop habitats.

Over time, however, some ground-dwelling primates, like gorillas, began to lose the function of the palmaris longus muscle as their reliance on forearm-based mobility diminished. As their environment and way of life evolved, so did their anatomy. Similarly, humans are now following a comparable trajectory. Since we no longer use our forearms for movement in the same way as our ancestors, the tendon associated with the palmaris longus has started to disappear in a portion of the population.

Currently, research estimates that about 10-15% of people worldwide no longer have this tendon. This gradual loss offers an intriguing look at how evolution operates. It’s not that the tendon suddenly vanishes; rather, the change occurs over countless generations as our bodies adapt to the demands—or lack thereof—of our environment. For those who still possess it, the tendon serves little to no functional purpose in modern life, which is why its disappearance has no adverse effects.

How to Check for the Tendon

Curious to know whether you still have this ancient tendon? There’s a simple test you can try at home. Start by placing your forearm on a flat surface with your palm facing upward. Then, bring your pinky finger and thumb together while gently lifting your hand off the surface. If you notice a distinct band in the center of your wrist, congratulations—you still have the tendon! If you don’t see the band, you’re among the group of humans for whom the tendon has faded away over generations.

This little experiment is not only a fun way to learn something new about your body, but it also serves as a reminder of how we’re all connected to our evolutionary past. Whether you have the tendon or not, your body tells a story of adaptation and resilience that stretches back millions of years.

The Bigger Picture of Human Evolution

The gradual disappearance of the palmaris longus tendon is just one example of how evolution continues to shape us in subtle but meaningful ways. While the changes may seem small, they add up over time, reminding us that evolution is an ongoing process. It’s a humbling thought that we’re all part of this ever-unfolding journey, and it’s exciting to think about what the future might hold for humanity as we continue to adapt to new environments and challenges.

Evolution doesn’t just tell us where we came from—it also hints at where we’re headed. By understanding and appreciating these small but significant changes, we can gain a deeper sense of connection to the incredible journey of life on Earth.

Share Your Experience

Did you try the test? Do you still have the tendon? We’d love to hear about your experience! Share your results in the comments and join the conversation about this fascinating aspect of our evolution. Don’t forget to pass this article along to your friends and family on Facebook so they can try the test too. It’s a simple yet engaging way to explore the wonders of our shared history and celebrate the incredible complexity of our bodies.

Let’s keep the conversation going—because understanding even the smallest aspects of our evolution can inspire awe and deepen our appreciation for the remarkable beings we are.