Humans May Not Be Done Evolving After All

According to a new study published in the Journal of Anatomy, “our forearms contain compelling evidence that we are still evolving, albeit it on a small scale, as the prevalence of a blood vessel called the median artery has increased significantly since the late 19th century.”  

The presence of this artery is important because during the embryonic stage of development this is the main vessel that transports blood to the forearm and hand. As the radial and ulnar arteries develop, they replace the median artery, making it an uncommon feature in the adult forearm, but now researchers from the University of Adelaide are finding a growing number of adults never lose their median artery, according to IFLScience.com.

“Since the 18th century, anatomists have been studying the prevalence of this artery in adults and our study shows it’s clearly increasing,” study author Dr. Teghan Lucas said in a statement. “The prevalence was around 10% in people born in the mid-1800s compared to 30% in those born in the late 20th century, so that’s a significant increase in a fairly short period of time, when it comes to evolution.” Lucas estimates that if this trend continues, a majority of people will have a median artery in their forearm by 2100.

While the exact benefits of retaining the artery still aren’t clear, the researchers speculate that this increases the overall blood supply to the forearm and hand, and it could eventually be used during surgeries to replace damaged vessels in other parts of the body. 

“This is microevolution in modern humans and the median artery is a perfect example of how we’re still evolving because people born more recently have a higher prevalence of this artery when compared to humans from previous generations,” senior author Professor Maciej Henneberg concludes.