Our bodies are living relics of evolution, carrying small, often overlooked features that connect us to our ancient ancestors. From goosebumps on a chilly day to the tendon you might spot in your wrist, these remnants tell a story that stretches back millions of years.
Human bodies are a patchwork of evolutionary remnants, carrying tiny clues that link us to our ancient ancestors. While modern life has drastically changed, some of these features have stuck around, occasionally surprising us with their quirky functions. From the shiver-induced goosebumps on our skin to the unexpected tendon visible in certain wrists, these traces of evolution tell a story that stretches back millions of years.
Discovering the Palmaris Longus: A Peculiar Tendon in the Wrist
One fascinating evolutionary artifact that some people still have is the palmaris longus tendon, found in the forearm. Not everyone has it – in fact, around 10-15% of the population lack this tendon entirely. This tendon was part of a larger muscle system, helping our tree-dwelling ancestors grip and swing from branches. Today, it’s largely unnecessary, a vestigial feature without a clear function, though it remains in the body structure of many humans.
Wondering if you have it? There’s an easy way to check. Lay your forearm flat on a table, with your palm facing up. Touch your pinky to your thumb and gently lift your hand. If a band-like structure rises along the center of your wrist, congratulations – you possess the palmaris longus tendon. If you don’t see this band, it’s likely that your body has already discarded this ancient feature, deeming it unnecessary.
Why This Muscle Remained… and Why Some People Don’t Have It
The palmaris longus is a small remnant of our evolutionary history, a part of a muscle group that was highly useful for primates who relied heavily on arm strength and grip. For our ancient ancestors, strong forearms were crucial for climbing, swinging, and surviving in the trees. As humans evolved and began walking upright, however, the need for a powerful gripping tendon lessened, and this muscle slowly started to fade in significance.
Today, the palmaris longus has little practical purpose in daily human activities. In fact, people without this tendon experience no disadvantage in grip strength or hand function. For some, the tendon might have simply disappeared due to genetic mutations that were not harmful and thus spread through generations without issue. In others, the tendon has stayed, a harmless reminder of an earlier phase of human evolution. The variation speaks to a broader principle in evolutionary biology: features that are no longer essential for survival tend to disappear over time, but the process is gradual and variable across different individuals and populations.
Evolution is an Ongoing Process
Many people mistakenly think that human evolution is something of the distant past, with no relevance to our current lives. But the truth is that evolution is always in motion, even if the changes are so subtle they’re hard to notice. Evolution doesn’t necessarily involve sudden leaps or dramatic mutations; rather, it’s a process of tiny, gradual adjustments. The palmaris longus tendon is an excellent example of this – some humans have it, some don’t, and it doesn’t significantly impact our lives either way.
This disappearing tendon is a sign of slow, ongoing change. As our lifestyles and environments evolve, our bodies subtly adapt. Traits that once played an essential role in survival, like the palmaris longus tendon or even body hair, are no longer as crucial in a modern setting where our survival depends less on physical agility and more on other skills and tools. However, the fact that these traits haven’t completely vanished indicates that evolution operates over long periods, allowing us to catch glimpses of it in our own bodies.
Goosebumps: Another Evolutionary Remnant
Another example of our evolutionary past is the phenomenon of goosebumps. While they may seem trivial, goosebumps serve as a reminder of our past. When we feel cold or frightened, tiny muscles at the base of hair follicles contract, causing the hair to stand upright. For our fur-covered ancestors, this reaction would trap an insulating layer of air between the hairs, helping to keep them warm. In situations of fear, it would make them appear slightly larger, perhaps intimidating a potential predator.
Although we’ve largely shed the thick fur coat, the reflex remains. Today, goosebumps serve little practical purpose for humans, but the mechanism is still triggered by the brain in response to cold or fear. It’s another example of how our bodies are influenced by evolutionary adaptations that, while now functionally redundant, were once essential for survival.
Wisdom Teeth: A Third Evolutionary Puzzle
Wisdom teeth are yet another example of evolution’s leftovers. Our distant ancestors had larger jaws that could accommodate an extra set of molars. These teeth were useful for a diet of coarse plant material, which required a lot of chewing power. As humans evolved, our diet shifted, and our jaws became smaller. However, the genetic blueprint for wisdom teeth remained. For many, this has become a source of dental problems, as these teeth often grow in crooked or become impacted due to lack of space in the modern human jaw.
Dentists often remove wisdom teeth to prevent future issues, but the fact that these teeth continue to grow in many people highlights the slow pace of evolutionary change. The gradual shift in diet and jaw size over centuries has yet to completely phase out wisdom teeth, although some individuals are now born without them – a sign that the change is slowly taking place.
The Unique Journey of Each Human Body
Evolutionary traits like the palmaris longus tendon, goosebumps, and wisdom teeth paint a fascinating picture of human adaptation. Each body is unique, carrying different evolutionary relics that tell a story of survival, adaptation, and change. Some of these features may fade over time, while others might remain, embedded in our DNA as subtle reminders of a different era.
Ultimately, our bodies are a testament to a complex history shaped by survival needs, environmental changes, and random genetic variations. We may not need the palmaris longus tendon or goosebumps to thrive today, but these features are part of what makes us human. They connect us to a lineage that has adapted, changed, and survived through countless challenges.
In a way, our bodies are living museums of the human journey, carrying traits that evolved to meet the demands of ancient environments and conditions. These remnants are a reminder that we, too, are part of the ongoing story of evolution, adapting to our world in ways we might not even realize. Who knows what future generations will retain – or lose – as our species continues to adapt to a world that’s always changing.
