A new study has found that some babies are being born without wisdom teeth, thanks to a ‘microevolution’ humans have undergone. In addition to the lack of wisdom teeth, more are being born with a rare additional artery in their forearm, as well as additional bones.
Microevolution is a change in gene frequency within a population, which can be observed over short periods of time. This change could be a result of mutation, migration, genetic drift, and natural selection.
Scientists in Australia, led by Dr Teghan Lucas of Flinders University in Adelaide, have been analysing the changes in humans over a short period of time, and their research has found that modern humans have shorter faces and smaller jaws due to our diets, leaving less room for teeth.
“This is happening in time as we have learnt to use fire and process foods more. A lot of people are just being born without wisdom teeth,” said Dr Lucas.
Babies are also being born with additional bones in their arms and legs, as well as with abnormal connections of two or more bones in their feet.
The prevalence of the median artery has also seen a significant increase since the late 19th century. This artery forms while a baby is in the womb and is the main vessel that supplies blood to the forearm and hand. During gestation, however, it disappears and is replaced by the radial and ulnar arteries.
“Since the 18th century, anatomists have been studying the prevalence of this artery in adults and our study shows it’s clearly increasing,” Dr Lucas said.
“The prevalence was around 10% in people born in the mid-1880s 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.”
If this trend continues, the study predicts that people born 80 years from now will all carry a median artery.
Lucas posits that this increase could be a result of gene mutations or health problems in both during pregnancy, or a combination of the two.
The study is evidence that humans are evolving at a faster rate than at any point the last 250 years. The authors suggest changes in natural selection could be a big reason for this microevolution.