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Teeth fossils are the key to unlocking human evolution.
Yes, it is true – according to this new research, molar teeth could be the answer to human evolution. You may wonder: what can teeth tell us about human evolution? A lot. An Australian study has spotted a common pattern in mammals and humans’ molar teeth, one that could help identify human fossils that are otherwise incomplete.
For years scientists have debated the evolution of our third molars, more commonly known as wisdom teeth. While the molars are often very small or fail to even develop in humans, those of other hominin species in our evolutionary tree were huge. Their chewing surfaces could be two to four times larger than those in an average modern human.
However, many scientists have long tried to explain the profound size change to dietary and cultural shifts considered to be unique to humans. Think cooking, for example.
A new study, published this week in the journal Nature, by a team of researchers led by evolutionary biologist Alistair Evans of Monash University in Australia offers an explanation that make us appear far less special.
Teeth can tell us a lot about the lives of our ancestors, and how they evolved over the last 7 million years.
declared Professor Evans in a recent press release.
Evans and his team came up with their conclusion after analyzing hundreds of fossilized teeth from modern humans and their ancestors alike, as well as those from chimpanzees, gorillas, and other similar apes.
They tried using several methods to gauge tooth size, including CT scans, but eventually discovered that the simplest method was the most accurate – multiplying a tooth’s width and length to create a rectangle representing crown size.
Additionally, the study suggests that the difference in Homo and Australopith tooth size could be indicative of differences in their respective diets.
Evan says that paleontologists have worked for decades to interpret these fossils and look for new ways to extract more information from teeth. Rather than viewing their evolution as the result of human-specific selective pressures, he proposes that the shrinking of wisdom teeth may be explained by basic developmental mechanisms that we share with most mammals.
Moreover, Evan’s research confirms that molars follow the sizes predicted by Professor Grant Townsend what is called ‘the inhibitory cascade’, a rule that shows how the size of one tooth affects the size of the tooth next to it.
Another author on the Nature paper was from the University of Adelaide’s School of Dentistry. The study examined teeth of modern humans, including those in one of the world’s largest collections of dental casts housed at the Adelaide Dental Hospital.
All in all, the findings of the study will be very useful in interpreting new hominin fossil finds, and looking at what the real drivers of human evolution were. As well as shedding new light on our evolutionary past, this simple rule provides clues about how we may evolve into the future.
Image Source: capitalotc.com.
