Have you ever wondered why we have certain traits that no longer seem to serve a practical purpose? Well, it turns out that many of these features are remnants inherited from our ancestors. They were once essential for their survival, but in our modern lives, they have become almost obsolete.
One prime example of this is the phenomenon of goosebumps. You might think it’s just a random occurrence, but it actually has its roots in our mammalian ancestors. When they were exposed to cold temperatures, goosebumps helped them increase their surface area to retain heat. While this response is no longer crucial for us, it serves as a reminder to grab a coat on a chilly day. We can even observe modern mammals engaging in this instinct, such as a pigeon puffing up its feathers to stay warm.
However, there is another trait that provides even more compelling evidence of evolution. It lies within our arms, specifically in our tendons. One particular tendon, known as the palmaris longus, shows clear signs of evolution. This tendon was once connected to an ancient muscle that helped arboreal primates, like lemurs and monkeys, move from branch to branch.
As humans and ground-dwelling apes like gorillas no longer rely on this muscle or tendon, it has gradually phased out in 10-15% of the human population. But evolution moves slowly, so nearly 90% of humans still have this vestigial trait passed down from our primate ancestors. You can even check if you have this tendon yourself. Simply 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, congratulations! You have the tendon connected to the palmaris longus.
On the other hand, if you don’t see this tendon, it’s a sign of ongoing human evolution. It represents a fascinating connection to our ancestral past, with those who have it carrying a tangible link to our evolutionary history. Those without it, however, provide clear evidence of how we are still evolving.
So, the next time you notice goosebumps or examine your wrist, remember that these small reminders of our evolutionary journey are all around us. They serve as a testament to our interconnectedness with the past and the reality that we are constantly changing and adapting. Embrace the marvel of evolution and the wonders it reveals about our existence.
