“Microevolution” is a thing. And it’s happening as we speak.
A new study published in the Journal of Anatomy found that humans are increasingly being born without wisdom teeth. Researchers also found that the median artery in the forearm, which used to form in the womb but disappear after birth, is sticking around more often after birth. These changes are showing up far more often than typical human evolution would suggest — and indicates that the human race may be evolving faster than it has at any point in the last 250 years.
“This is what we call ‘microevolution of modern humans,’” said Dr. Teghan Lucas, a professor at the College of Medicine and Public Health at Flinders University in Adelaide, Australia, who worked on the study.
Lucas, along with University of Adelaide professors Maciej Henneberg and Dr. Jaliya Kumaratilake, found that as human faces have gotten shorter, our mouths have consequently become smaller — thus, less room for wisdom teeth. Humankind’s increased ability to chew food, along with the rise in processed foods, also seems to have accelerated this evolutionary trait.
In a news release from Flinders University, the researchers gave additional details about the median artery, which provides additional blood flow to the human forearm and hand. Typically, this artery disappears in utero as the fetus develops its radial and ulna arteries. But this is changing.
People born in the mid-1880s, for example, retained this artery approximately 10% of the time. For those born in the late 20th century, however, the prevalence is 30%, the Independent reported.
“So that’s a significant increase in a fairly short period of time, when it comes to evolution,” Lucas said, adding that the increase may have come from mutations of genes involved in median artery development and/or health problems in mothers during pregnancy.
If this trend continues, Lucas said a majority of people will have a forearm median artery by the year 2100.
The study also revealed an increased prevalence in spina bifida occulta, abnormal connections of two or more bones in feet, and the fabella (a small bone in the back of the knee joint). Presence of the thyroidea ima artery was found to decrease over time, then disappear completely by the end of the 20th century.