Evolution continues to shape us — not just in theory, but in the very structure of our bodies. From our ancient primate ancestors to modern Homo sapiens, traces of evolution remain visible in surprising ways.

Take goosebumps, for instance. This reaction isn’t random; it’s a leftover survival mechanism from our mammalian ancestors. When early humans faced cold or danger, tiny muscles around hair follicles contracted, lifting the hair to trap heat or make them appear larger — just like cats puffing up when frightened. Today, it’s mostly a useless reflex reminding us of our evolutionary past.

But the most fascinating clue lies in our wrists. About 10–15% of humans lack the palmaris longus tendon, a muscle once used by primates to swing between branches. To test if you have it, place your forearm palm-up and touch your pinky to your thumb. A visible band means you still possess this ancient feature.

Those without it? You’re proof of evolution in progress.
Our bodies, from goosebumps to vanished tendons, are living records of a story millions of years in the making — one that still continues today.