But there is one trait that clearly shows proof of evolution: The most compelling evidence lies within our arms, specifically in our tendons. One tendon, which has gradually phased out in 10-15% of the human population, highlights that humans are still evolving.

This tendon is connected to an ancient muscle called the palmaris longus.

This muscle was essential for arboreal primates, such as lemurs and monkeys, to help them move from branch to branch. As humans and ground-dwelling apes like gorillas no longer rely on this muscle or tendon, both species have gradually lost this function.

However, evolution moves slowly, so nearly 90% of humans still have this vestigial trait, passed down from our primate ancestors. To see if you have this tendon, place your forearm on a table with your palm facing up. Touch your pinky finger to your thumb and slightly lift your hand off the surface. If you see a raised band in the middle of your wrist, you have the tendon connected to the palmaris longus.

If you don’t see this tendon, congratulations—you’re showing an evolutionary change! The presence or absence of this tendon is a fascinating connection to our ancestral past, with those who have it carrying a tangible link to our evolutionary history. Conversely, those without it represent clear evidence of ongoing human evolution.