Shape of human teeth can help to reconstruct genetic relationships

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Shape of human TEETH can reveal the owner’s genetic history and could be used to identify people in forensic investigations and trace the evolution of our species using fossils

  • Researchers assessed different traits of teeth and their combinations 
  • Found links between physical characteristics and genetic links in other studies  
  • Claim teeth can be used to understand genetic lineages if DNA and other remains are unavailable 

By Joe Pinkstone For Mailonline

Published: | Updated:

The unique shape and form of teeth could make them a useful tool in tracing a person’s genetic history.

A study found that some characteristics of dental remains — such as crown groove patterns, cusp size, number of roots, and the presence of wisdom teeth — can act as pieces of a jigsaw puzzle to help discern a person’s identity and genetic makeup. 

These techniques can then be applied in various ways, to both modern and ancient remains and it could, for example, help identify unknown individuals in ongoing forensic cases where skeletal or DNA remnants have been destroyed. 

It could also be used to unpick the mystery of the human race’s origin from fossilised remains or investigate the prehistoric movement of ancient populations.

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A study found that some characteristics of dental remains — such as crown groove patterns, cusp size, number of roots, and the presence of wisdom teeth — can act as pieces of a jigsaw puzzle to help discern a person’s identity and genetic makeup 

Teeth grow rings like trees which ‘act as a ‘faithful archive of life’ 

Human teeth act like tree rings and store intimate details about a person’s life, a study has found.  

The research by American scientists found a material in teeth called cementum develops a fresh layer every year. 

Studying subtle changes in its growth can provide key details such as when an individual was pregnant, seriously ill or in prison.  

Cementum is a dental tissue that covers the tooth’s root.

It grows a new layer roughly every year.  

The cementum’s microstructure is visible only through microscopic examination.

Analysis can reveal the underlying organisation of the fibres and particles that make up the material of this part of the tooth.

The microscopic layers can be illuminated using a variety of laboratory methods. 

Each layer has slightly different structure as the body forms i=the cementum .

When the body is under strain, the structure is very different to under normal conditions. 

How the body is under strain can also be determined as well as when.  

Research from the University of Tübingen published in the journal PNAS used an algorithm to compare DNA data to commonly seen dental traits.

This allowed the researchers to find links connecting genetics and teeth characteristics, gathered by assessing more than 130million possible combinations. 

Teeth are extremely durable and often survive long after other tissues that can be used to identify a person have perished. 

However, until now, being able to interpret the information they hold has been difficult. 

‘Dental traits can be used in population genetic studies when DNA is not available,’ says Hannes Rathmann, who led the research.

‘Most human dental traits probably arose by chance as a result of genetic drift.

‘That is an evolutionary process that is considered to be neutral, having no particular advantages or disadvantages for individuals or the population.’

The scientists say that researchers in future should pay attention to the appearance of the teeth they discover.   

This will be of particular use if DNA cannot be retrieved due to poor preservation or when restrictions apply to destructive sampling, as in paleoanthropological research, says co-author Dr Hugo Reyes-Centeno.

‘We propose that future studies should prioritise the most effective dental traits and trait combinations found in our study, as they allow more accurate conclusions to be drawn about genetic relationships,’ he adds.  

A recent study found human teeth act like tree rings and store intimate details about a person's life. Left, a look at the second molar of a 35-year-old female who had children at ages 19 and 24. Middle is a zoomed-in section of the left image. Right, the cementum, which presents two distinct darker 'rings' that correspond to the two reproductive events

A recent study found human teeth act like tree rings and store intimate details about a person’s life. Left, a look at the second molar of a 35-year-old female who had children at ages 19 and 24. Middle is a zoomed-in section of the left image. Right, the cementum, which presents two distinct darker ‘rings’ that correspond to the two reproductive events