Human beings do not have to wait to develop genetic mutations to achieve telepathy or even superpowers, as a new study shows that our species continues to evolve in unique ways; the changes are subtle in our anatomy, but they are proof of how unpredictable evolution itself can be.
Research led by Teghan Lucas of Flinders University and Maciej Henneberg and Jaliya Kumaratilake of the University of Adelaide has shown a significant increase in the prevalence of the median artery in humans since the late 19th century.
Homo sapiens has not yet finished its evolution
That’s how it is. Our forearms contain compelling evidence that we are still evolving, from the appearance of a blood vessel called the median artery that has increased significantly since this time.
During the embryonic stage of our development, the median artery is the main vessel that carries blood to the forearm and hand but disappeared as the radial and ulnar arteries replaced it while the baby was still developing in the womb, becoming a feature. uncommon in the adult forearm. However, findings published in the Journal of Anatomy reveal that not only is the median artery not disappearing in some individuals, they represent a growing group ( about one in three people).
“Since the 18th century, anatomists have been studying the prevalence of this artery in adults and our study shows that it is clearly increasing. The prevalence was around 10% in people born in the mid-1880s compared to 30% in people born in the late 20th century, making it a significant increase in a fairly short period of time, as far as evolution is concerned, “the experts explain.
Arms with the three arteries
According to experts, the median artery is currently present in about 35% of people and they predict that all those born within 80 years will have a median artery if this trend continues.
“The median artery offers benefits because it increases the blood supply in general “, clarifies Maciej Henneberg, co-author of the work. “This is microevolution in modern humans and the median artery is a perfect example of how we are still evolving because more recently born people have a higher prevalence of this artery compared to humans of previous generations.”
Investigation
To compare the dominance of this blood channel, the scientists examined 80 cadaveric limbs, all donated by Australians of European descent. Almost all donors were born in the first half of the 20th century.
Looking at how often they found a thick median artery capable of carrying a good blood supply, they compared the figures with records taken from a literature search. The fact that the artery appears to be three times more common in adults today than it was more than a century ago is a surprising finding that suggests that natural selection is favoring those who hold on to this extra amount of blood.
“This increase could have been the result of gene mutations involved in the development of the middle artery or health problems in mothers during pregnancy, or both actually,” says Lucas.
Microevolution
In case our readers are wondering, the median artery does not pose any real health risk but it is a beneficial anatomical feature, as it increases the overall blood supply to the forearm and hand. It is hoped that it can even be used during surgeries as a replacement for damaged vessels in other parts of the body.
Other examples of changes in human anatomy from this microevolution include the prevalence of spina bifida occulta, abnormal connections of two or more bones in the feet, increased absence of wisdom teeth, middle thyroid artery, and fabella (small bone in the back of the knee joint).
Referencia: Teghan Lucas et al. Recently increased prevalence of the human median artery of the forearm: A microevolutionary change. Journal of Anatomy, published online September 10, 2020; doi: 10.1111/joa.13224
