Show me your teeth, let me tell you who you are. ”This word dedicated to the 19th century naturalist George Cuvier could not have been more accurate. Our teeth, which we do not have a single day of use, offer important clues not only about our own personal life, but also about the evolutionary history of our species.
Upper teeth of a Neanderthal who lived about 40,000 years ago. A: Debbie Guatelli-Steinberg
Teeth, which are locked to their gums, can offer remarkable details about the creature they are in. The creature mentioned here can be us modern humans, our ancient ancestors, or any female being.
Fossilized teeth can be called time capsules that illuminate human evolution, including various diets, prolonged childhood, and other unique features of our species. Researches are trying to understand what fossilized teeth can tell us about our ancient ancestors.
(Neanderthal Teeth Provide Information About Their Daily Life)
Examining ancient diets through dental chemistry
The chemical evidence of our diet is based on whatever you eat. Plants using different photosynthesis pathways incorporate C-13 and C-12-called carbon isotopes into their cells. Chemists know that there are more C-13s in the cells of tropical grass and reeds (C4 plants), while other plants such as trees and shrubs (C3 plants) have relatively fewer C-13s.
Chimpanzees climb trees and consume fruits and nuts grown there. A: Caelio
Since enamel is formed during childhood, it locks the rate of digested carbon isotope to its dense mineral structure. This ratio, preserved unchanged for millions of years, allows anthropologists to determine which plants are used to chew which plants.
Our closest primate relatives, chimps, consume a wide variety of foods just like us, but fruits, seeds and nuts come from the main trees and shrubs that form the basis of their diet. Analyzing the rate of carbon isotope in tooth enamel, researchers found that 3.5 million years ago, Lucy’s species, Australopithecus afarensis, adopted a diet different from that of chimpanzees.
(Human Teeth May Be Reduced Due To Tool Use)
These human ancestors ate not only from chimps and bushes and trees, but also from tropical grass and reeds. This was something chimpanzees did not eat, even if it was easily accessible.
This change in their diet was also associated with the diversity of environment that Lucy and her species live. There was a transition from woodlands to meadows. The teeth show that our ancestors came out of the forests to new lands and started eating what they found there.
Research on other chemical elements found in tooth enamel also showed that the early members of Homo habilis, who lived in South Africa, consumed large amounts of meat. This result indicates that there is more than a variety of nutrition patterns known.
In reality, the situation is no different than it is now. The foods we consume have an unimaginable variety and it is highly possible that this variety adapts to different environmental conditions and contributes to our survival skill and ultimately our evolutionary success.
Counting age rings
One of the unique features of our species is the long childhood period. It also takes a longer time for the modern human to be the breeding adult of the species that has the longest childhood among primates. The duration of the development and immersion in the jaw bone reflects this fact. The first molars in chimpanzees usually appear around the age of four, while the molars in humans begin to appear two years later, about six years old.
Tooth enamels grow in layers, just like trees. The rings in the trees reflect the annual growth, while the growth lines in the tooth enamel show a shorter period of time. On the outer enamel, both daily growth lines and longer growth, such as eight days, can be seen.
Anthropologists count these lines of growth through fossil teeth to grasp how fast our ancestors’ teeth develop and to see if they look more like chimpanzees or modern humans. Even in individuals who have died before all their teeth have developed, it is possible to say how old they were when they counted these growth lines and died. Thus, researchers can compare the dental development in our ancestors with the dental development of a modern age man.
It is understood from such research that in the early stages of human evolution, in the type of Lucy, the teeth developed faster, which indicates that our ancestors grew faster than us. In the later stages of evolution, with Homo erectus, the development of teeth and the process of growth begin to lengthen. Spending a longer childhood, although not certain, is a good opportunity for people to learn and master complex skills that are critical to survival and survival.
(Teeth Reveal Diet During Irish Famine)
Researchers use not only growth lines but also wear on tooth enamel to comprehend human evolution, and interesting results are obtained from the analysis of these abrasions. For example, in Neanderthals, evidence of psychological tension events such as illness and malnutrition, which adversely affected their development during childhood, can be seen on the tooth enamel. Upon counting the growth lines on the tooth surface, some of these events are said to have lasted up to three months.
The red arrows show the lines of wear on the tooth surfaces of ancient Inupiaqs living in Alaska. A: Debbie Guatelli-Steinberg
These findings become even more meaningful, given that Neanderthals lived under difficult conditions. Similar wear is observed in the teeth of today’s hunter gatherers as a result of the examinations. Between the years 1300 and 1700 AD, the ancient human community of Inupiaq, who lived in Alaska, has long disruptions in tooth development.
What will our teeth tell?
Perhaps 10,000 years from now, anthropologists will examine our fossilized teeth. If they analyze our dental enamel, they will be able to see which of us is vegetarian and which of us eat a lot of meat. Perhaps it will surprise them that individuals from the same community have large differences in their diet, but more likely they will interpret these differences among individuals as a natural extension of evolutionary biology, although our brains that are larger than other primates allow behavioral flexibility, including the ability to consume a variety of foods.
The anthropologists of the future will be amazed at the variety of dental problems we experience. While only a few different dental problems are encountered in fossilized human teeth, a wide variety of ailments can be observed in our remains, from malocclusion (irregular tooth closure), to third molar impaction, from caries to gingivitis.
Future scientific studies may use the idea of ”evolutionary conflict” that the hunter-gathering diet adopted by our ancestors did not prepare for the soft and sugary foods we consume abundantly today. Basically we are not adapted to the modern Western diet. The foods consumed by our hunter-gatherer ancestors were foods that are difficult to chew and do not contain refined sugar, since the soft foods we consume do not stimulate jaw development during childhood, malocclusions may occur and sugary foods provide favorable environments for the growth of bacteria that can lead to tooth decay.
A group of anthropologists discovered that bacterial DNA was extracted from the calcified plate on an ancient tooth, and bacteria species that led to tooth decay became more common with the development of agriculture. These bacterial species had developed particularly in the human mouth during the Industrial Revolution, with the first production of processed sugar. The effect of processed sugar on our teeth still continues today.
So how will future anthropologists interpret the myriad ways people change their teeth? In Western cultures, people tend to suffer to artificially whiten their teeth. According to a study conducted in England, white teeth are more attractive, especially in women. Studies show that white teeth, which are considered as an indicator of youth in the choice of spouses, are a reason for preference.
A Geisha who paints her teeth in black. A: Tsukioka Yoshitoshi
So, how should he explain the practice of teeth blackening done in some traditional Asian cultures to look good again? Moreover, how will the anthropologists of the future make sense of applications such as notching the teeth, sharpening the ends, carving and placing gold and jewelry, or removing them all at once? It is certain that these applications, which have been done in different societies in the past and many of them are still being made, will be the subject of discussion by next generation researchers.
Remember that the next time you forget to brush your teeth or find yourself at a dentist’s table, future anthropologists will examine your teeth that will be fossilized.