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Teeth That Tell a Story

In 2001, a team of archaeologists were digging at a site in Siberia, a region in northeastern Asia. The team found many interesting artefacts, including ancient tools made from stone and ivory. But the biggest discovery of all was a pair of human teeth. The archaeologists determined that the teeth had come from two unrelated children who lived about thirty-one thousand years ago. These teeth were by far the oldest human remains ever found in the area. The archaeologists realised that they had discovered evidence of a previously unknown population. They called this newly discovered group the Ancient North Siberians.

But who were the Ancient North Siberians? Where did they come from, and where did they go? Scientists wanted to learn more, so they collected some DNA from inside the teeth. DNA contains information that has been passed down through generations of family members. By comparing DNA samples from different groups, scientists can learn how the groups are related. The DNA collected from the teeth helped scientists reach a surprising revelation: the Ancient North Siberians shared a lot of DNA with an earlier group of people who had lived far to the west.

How did the Ancient North Siberians end up living so far away from their genetic relatives? Researchers believe that the answer has to do with some very chilly weather. During the last Ice Age, the earth experienced frigid temperatures. Solid sheets of ice covered most of the planet. In order to survive, people from Europe and western Asia migrated to warmer areas in the east. They followed animals such as mammoths, which they relied on for food. Eventually, some of these people ended up in northeastern Asia. It was these people and their descendants who became the Ancient North Siberians.

Something else interested scientists about the ancient teeth. They realised that the DNA in the teeth had similarities to the DNA of early Native Americans. Today, northeastern Asia and North America are separated by the Bering Sea. But thousands of years ago, the two continents were connected by a narrow strip of land that scientists call the Bering land bridge. Based on DNA evidence, it appears that some Ancient North Siberians mixed with another group of people from eastern Asia, creating a new population group. Then members of this new group followed the land bridge all the way to North America. Some researchers believe these migrants walked across the land bridge on foot. Others think that they followed the coast of the land bridge in boats. However they travelled, most scientists believe these people were probably the first humans ever to set foot in North America.

It is amazing to think how much scientists have been able to learn from the discovery of two small teeth. The teeth not only provided clues about the Ancient North Siberians. They have also helped researchers to better understand human history and the relationships between populations that lived thousands of kilometres apart.