Some babies are now being born without wisdom teeth, and more people have a previously rare additional artery in their forearm, as humans undergo a “micro-evolution”, a new study suggests.
Scientists in Australia have discovered several changes in humans which are appearing over a short period of time.
Dr Teghan Lucas, of Flinders University in Adelaide, said faces are also becoming shorter, due to changes in our diet, and our smaller jaws mean there is 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,” she said.
The research team also found an increasing prevalence of people being born with additional bones in their arms and legs as well as shorter faces, or with abnormal connections of two or more bones in their feet.
In addition, the investigation by Dr Lucas, along with University of Adelaide professors Maciej Henneberg and Jaliya Kumaratilake, showed a “significant increase” in the prevalence of the median artery since the late 19th century.
The artery forms while a baby is in the womb and is the main vessel that supplies blood to the forearm and hand, but it disappears during gestation 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 per cent in people born in the mid-1880s compared to 30 per cent 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.”
“This increase could have resulted from mutations of genes involved in median artery development or health problems in mothers during pregnancy, or both actually.”
She added: “If this trend continues, a majority of people will have a median artery of the forearm by 2100.”
Ms Lucas said the study demonstrates that humans are evolving at a faster rate than at any point in the past 250 years.
The investigation's authors suggested changes in natural selection could be the major reason for micro-evolution.
The research is published in the Journal of Anatomy.
Additional reporting by PA
