This physiological response may not serve a significant purpose in modern life, but it still reflects our evolutionary history. For example, when facing cold weather, you might notice a pigeon puffing up its feathers to stay warm. This action is a clear reminder of evolution in action.

Additionally, animals such as cats will puff up their fur when they feel threatened, like when they’re startled. This instinctive response is a defense mechanism designed to make the animal appear larger and more intimidating to potential predators.

However, there’s one trait that undeniably highlights evolution’s ongoing process.

A fascinating example of evolution can be found in our arms, specifically in the tendons. In fact, about 10-15% of humans have lost a particular tendon, demonstrating that human evolution is far from complete.

This tendon is linked to the palmaris longus muscle, which was once essential for arboreal primates like lemurs and monkeys. This muscle helped them move between branches. As humans and ground-dwelling primates like gorillas no longer need this muscle, it has gradually diminished over time.

Despite this, evolution moves slowly, so nearly 90% of humans still retain this vestigial tendon inherited from our primate ancestors. To check if you have this tendon, place your forearm flat on a table with your palm facing upward. Bring your pinky finger and thumb together, and gently lift your hand off the surface. If you see a raised band in the middle of your wrist, you still have the tendon connected to the palmaris longus.

If you can’t see this tendon, it means you've experienced an evolutionary change!

The presence or absence of this tendon offers a fascinating link to our evolutionary roots. Those who still have it carry a tangible connection to our ancestors, while those who lack it show evidence of ongoing human evolution.

It’s truly amazing how our bodies still carry traces of our evolutionary past. Even seemingly insignificant or outdated physical traits offer us profound insights into the journey of evolution.