Human evolution is still ongoing, even if it happens too slowly to notice. One subtle example is a wrist tendon linked to the palmaris longus muscle, which 10–15% of people no longer have.
This muscle is important for animals like monkeys that rely on their forearms to move, but ground-dwelling apes — and now humans — have gradually lost its function. While nearly 90% of people still have the tendon, it’s slowly being phased out through evolution.
You can check if you have it by placing your palm up, touching your thumb to your pinky, and lifting your hand slightly. A visible band in the center of your wrist means the tendon is present; if not, you may be among those who’ve already lost it.