Evolution’s bite
We brush them every day, flash a smile, chew through meals, but it’s easy to forget the amazing role that teeth have played over the course of evolution.
Our teeth have evolved over millions of years to become the powerful grinding machines that they are today. Their mysterious origin lies in ancient sea-dwellers that roamed the oceans over half a billion years ago — read on for a mouthful of history…
Palaeontologists have recently discovered that teeth did not originate in the mouth for the purpose of eating; they were in fact originally designed as head armour. Through millions of years of evolution, some of these scales found a new purpose in the mouth, where they became indispensable tools to be adopted by almost every vertebrate since. The earliest teeth were little more than sharp, conical structures, and for many animals of the so-called ‘lower classes’ (think fish, reptiles, amphibians), teeth have remained fairly simple and un-specialised.
With the advent of mammals came two major dental overhauls. Mammals are born with a limited set of ‘milk teeth’, that by and large have erupted through the gums at birth, or shortly after as with humans. These baby teeth act as provisional placeholders for the larger set of permanent gnashers, which range in number across species from 2–74. Humans have 32. Permanence is an optimistic term however; on the planes of Africa many a senior lion can be seen creeping across the savanna with accessed, missing or broken teeth. Indeed, a hallmark of African wild dogs is the willingness of younger adults to chew and then regurgitate meat for their elders, to prevent them dying of starvation.
The rise of warm-blooded animals (endothermy) was also accompanied by a second major overhaul: tooth specialisation. Generating one’s own body heat has a lot of advantages, such as enabling survival in cooler climates, higher travel speeds and providing stamina for predator avoidance and parental care. But endothermy comes at a cost: mammals burn 10 times as much energy at rest as reptiles of similar size do. Other vertebrates capture, contain and kill prey with their teeth. Mammalian teeth, on the other hand, are designed to get the most bang for every bite. To do that, they must chew with incredible precision.
Fast forward a couple of aeons however, and these remarkable evolutionary structures now find themselves in a profound contradiction in humans. They are the hardest parts of our body and yet are incredibly prone to decay, but this was not always the case. Cavities are rarely found in the fossils of our fore-bearers. So where did it all go wrong?
The simple answer is diet. Post-industrial foods have levels of sugar unprecedented in the history of our planet. The resulting mismatch between our biology and our new-found environment explains much of the issues that afflict us today.
The mouth is a fragile ecosystem of microbes competing for resources. The problem is that sugar favours the acid-producing bacteria which cause teeth to rot. More acid means more of these bacteria grow, further out-competing the healthy ones that would normally keep them in check.
The good news is there are various things you can do to keep the harmful bacteria at bay. Here are some of the most important ones.
- Avoid sugary drinks and processed foods where possible. These foods provide harmful bacteria with the acid and sugar they need to thrive.
- Brush twice a day with a fluoride toothpaste. Fluoride helps remineralise the enamel making it less vulnerable to acid attack. Some premium toothpastes also have hydroxyapatite (the stuff which teeth are made of) which is even better at keeping your teeth strong.
- Floss regularly to remove bacteria in-between teeth. This is where 80% of cavities form.
- Visit the dentist twice a year to spot cavities early and get a professional cleaning to remove the pockets of bacteria that the brush & floss can’t reach.
All of these measures are designed to maintain a healthy mouth. However, it is worth remembering that the imbalance will persist for as long as modern diets rely so heavily on sugar — a luxury that our cave-dwelling ancestors rarely got to enjoy…
Floe Oral Care will be launching in August 2020 with a mission to eradicate tooth decay. For more digestible health news sign up to our bitesize newsletter at: www.getfloe.com
