Human evolution is not a relic of the past. In fact, it is still busy working at a surprisingly rapid pace.
One of the tell tail sign is right in our mouth: the changes of our wisdom teeth.
The Ancestral Role of Wisdom Teeth
Seven million years ago, our ancestors' jaws and teeth were similar to those of modern chimpanzees.
Our diet back then was purely tough and raw foods like roots, nuts, leaves and raw meats, which requires all the strength from the bigger jaws and bigger set of teeth.
The incisors were relatively large; canines were much longer and very pointy.
All the molars and premolars were quite large and the cusps (bumps) on the surfaces were more prominent.
The third molars - as known as - wisdom teeth were much needed to help with processing such raw diets and were essential for our survival.
Teeth were arranged in the jaw in a rectangular or U-shape which had more space for them to fully develop.
Why Wisdom Teeth Became Problematic?
Since we learned how to control fire, to cook and process food for easier consumption. As a result, our jaws gradually became smaller, shorter and changed into an arc shape, while the number of teeth remained the same.
This mismatch created a headache problem for so many modern humans who do not have enough room for their third molars to erupt properly.
These impacted wisdom teeth are trapped beneath the gums. They are growing at very odd angles and often have to be removed through surgical extraction.
Evolution in Real Time
Interestingly, not everyone develops wisdom teeth at all. Genetic studies suggest that more babies are being born without this third set of molars altogether.
This indicates a significant genetic shift, with natural selection may be gradually eliminating traits that no longer provide an advantage - or that actively cause harm.
A Reminder That Evolution Continues
The case of wisdom teeth is not unique. Human race is witnessing "micro-evolution" which has been starting and will continue for the coming generations, such as the decreasing prevalence of the appendix, changes in lactose tolerance and shifts in disease resistance.
What and how we are doing with our lifestyles, the changes in our cultural behaviors, technologies innovation will continue to shape who we are. Evolution hasn't stopped at all.
Blackheath Dental Team