Human teeth have changed in their appearance and function to reach their present form. In the examination of archaeological teeth, distinct changes are evident, which leads to hypotheses about people living long ago.
Tooth fossils tend to remain remarkably preserved, which enables researchers to have an illuminating glimpse into the teeth of bygone eras. Humans today display smaller teeth and smaller jaws when compared to people who lived 25,000 years ago. The canine teeth of some people living long ago were much larger than current human teeth. Molars also differed in size depending on the era of the teeth and the geographic location.
Another distinct difference between teeth of today and ancient teeth is the wear patterns. Teeth found by archaeologists have typically exhibited extreme wear, often down to the roots. This wear also tended to occur earlier in life, indicating a faster rate of wear. Researchers hypothesize that diet played an important role in how teeth wore down. It's possible that ancient people with larger incisors had diets that included large and tough fruits. Those with smaller incisors may have feed on smaller foods such as seeds and tiny fruits, which would have necessitated less strenuous biting and chewing.
The investigative process for exploring ancient teeth has typically involved counting pits and scratches using microscopic images. This type of research could be imprecise due to human error. A newer investigative process involves software that creates a map of dental topography, similar to geographical maps. The software measures the slope and elevation of tooth fossils, which provides information about the human owners of the teeth.
Researchers have also explored the origins of dental disease by studying DNA collected from tooth fossils. Researchers discovered a change in bacterial DNA that seems to correspond with dietary changes. The onset of farming changed people's diets, and the foods consumed became more processed instead of the hunting-and-gathering diets that people had consumed. Gum disease became more prevalent with increased consumption of wheat and barley. Tooth decay also became more prevalent, especially as people began eating more wheat and sugar.
Wisdom teeth also indicate evolution of humans over time. Humans in today's world usually do not have room to accommodate the four additional wisdom teeth that typically erupt in early adulthood. Hypotheses abound about the reasons for this lack of room, including changes in diet and living conditions for people. It's possible that early humans needed wisdom teeth for diets that consisted of coarse foods like meats, nuts, roots and leaves. Humans would have needed stronger chewing power and more teeth to handle these tougher foods. Foods in modern society don't require the same chewing capabilities since the invention of niceties such as knives and forks for cutting up bite-sized pieces for eating. The more vigorous chewing demanded in ancient times could have had increased the size of jaw muscles. Larger jaw muscles may have led to larger jaws overall and more room for wisdom teeth. It's also possible that poor diets and a lack of proper hygiene have led to the common incidence of wisdom teeth impaction. Even sleep positions throughout childhood could have an effect on how wisdom teeth erupt when they finally come in.
Softer foods common today may be contributing to issues with crooked teeth as well. Tooth disarray can also contribute to gum disease over time due to incorrect spacing between teeth. Front teeth and jaws have the job of tearing food and making it small enough to chew. Molars are in charge of grinding food up for swallowing. With softer foods, the human jaw hasn't had to work as hard and has shrunk, and crooked teeth have been a result.
Explore evolution and its correlation with teeth by visiting these resources and websites:
- An Evolving Dentition: Human Teeth from an Evolutionary Perspective
- Function and Form of Teeth in Human Evolution
- A Paleontological Perspective on the Evolution of Human Diet
- "Evolving to Eat Mush": How Meat Changed Our Bodies
- Our Ancestors Had Much Better Teeth
- Is Lack of Room for Wisdom Teeth Proof of Evolution?
- Why Do We Have Wisdom Teeth?
- Teeth Offer Clues to Human Diet Evolution
- On the Evolution of Human Jaws and Teeth: A Review
- Human "Dental Chaos" Linked to Evolution of Cooking
- Using Lasers to Check Ancient Teeth for Clues to Human Evolution
- Tracking Diet Transitions During Infancy From Teeth
- Early Transitional Humans
- Ancient Teeth Reveal Evolution of Cavities
- Thick Tooth Enamel Sheds Light on Human Evolution
- Diet and the Evolution of the Earliest Human Ancestors
- Why Do We Have Wisdom Teeth?
- Ancient Neanderthal Skulls Reveal Insights Into Human Evolution
- Milk Teeth
- The Recent Roots of Dental Disease
- Gradual Change in Human Tooth Size in the Late Pleistocene and Post-Pleistocene