How to check if you’ve lost this tendon on your arm to evolution

Our bodies are truly incredible, yet we rarely appreciate the marvel of evolution they represent. Humans have evolved from primates into complex, society-building beings—yet biologically, we’re nearly identical to our ancestors from 20,000 years ago.

While evolution continues, it moves so gradually that we hardly notice. A great example? The palmaris longus tendon in your wrist. This muscle, vital for tree-dwelling primates, has been disappearing in humans—about 10-15% of people no longer have it. Want to check yours? Rest your forearm palm-up, touch your pinky to your thumb, and lift your hand slightly. If a tendon pops up in the middle of your wrist, you have it! If not, you’re among those evolving away from it. Did you find yours?