Scientists have found a simple mathematical formula to explain the development of our teeth. The formula is a completely new tool that scientists can use to investigate human evolutionary history, and it might even settle important questions about our ancestors. Questions such as who the earliest members of the Homo family tree, 2.5 to 3 million years ago, were.
“We have found a mathematical rule that can objectively evaluate the evolution of different parts of the body,” says lead-author Professor Jukka Jernvall University of Helsinki, Finland.
Teeth can reveal lifestyle and behaviour
Teeth are important tools in evolutionary research as they are relatively hard and often better preserved than skulls and bone — and they can also reveal how extinct species once lived.
“Teeth are lovely fossils. Much of our knowledge of human evolution comes from dental studies,” says Professor Peter Kjærgaard, director of the Natural History Museum of Denmark. According to Kjærgaard, who was not involved in the new research, the study gives us another important tool for using teeth to investigate the evolutionary history of our species.
“I’m excited to see the analytical power of the potential to make testable predictions that the group is promising. It will be a big step forward,” he says.
Our early ancestors tended to have larger molar teeth, which were positioned further back along the jaw. This relationship was generally consistent among species, though tooth size was greatly variable. But this pattern switched in the Homo genus. Now, the first molar tooth (M1) was the largest and the teeth on either side were smaller.
“In this context, the new study explains why we are now losing our wisdom teeth — it’s simply a pattern that was already established at the beginning of our family tree,” says Jernvall. So long as you know the species, the model can precisely describe tooth development and predict the size of teeth in the dental arch based on a single tooth.
— Source: www.sciencenordic.com
