DNA From 12,000 Year Old Skeleton Provides Needed Evidence

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DNALike the colorful grasshopper recently discovered in Oaxaca, science has once again stumbled upon a spectacular discovery, by happenstance, in Mexico. In a watery cave north of Tulum, the almost completely intact skeleton of a teenage girl was found. The DNA of a molar from the 12,000-13,000 year old skull has provided much needed evidence.

While mapping caves that had filled with water, divers found the skeleton in 2007. Tulum, on the eastern edge of the Yucatan Peninsula, is famous as the home of the only surviving pyramid/ruins in Mexico that were built overlooking a large body of water, the Caribbean Sea. It is in the state of Quintana Roo.

In one of the caves being mapped, there was an enormous underground chamber. Alberto Nava was one of the divers. He described the general feeling of awe upon entering the huge cavity. Nava said that the ground seemed to disappear out from under the dive team and they were unable to see across to the other side of the chamber. The name they gave the chamber is Hoyo Negro, Spanish for black hole.
When the crew returned a few months later, they managed to reach the bottom of the 100 foot high chamber. The floor was strewn with animal bones.

They also found the young girl’s skull. It was lying upside-down on a ledge. Nava explained that the skull had a “perfect set of teeth and dark eye sockets looking back at us.” They named her Naia, who was a water nymph in Greek mythology. The divers found a team of scientists to help them research the awesome find.

Naia's Skull
Naia’s Skull

Naia was 15 or 16 years old when she fell into that cave’s deep chamber. At that time, it was not filled with water. According to James Chatters, the lead author for the study, her pelvic bone was broken, indicating a long fall. Chatters works for Applied Paleoscience which is a consulting firm out of Bothell, Washington.

The analysis was reported on Thursday in Science magazine. Researchers from Canada, Denmark, Mexico and the United States all contributed. The study attempts to use Naia as a way to puzzle out and perhaps reinforce the theory that human beings came to the Americas via a land bridge that connected Asia to what is now Alaska. The DNA provided by the 12,000 year old skeleton could give science the evidence it needs to prove this theory.

The general belief amongst mainstream science is that the earliest Americans came from ancestors of Siberian descent who lived on the ancient span, Beringia, which is now underwater. They are believed to have crossed the Bering Strait and entered North America after 17,000 years ago. Indeed, there is genetic evidence pointing to a connection between the indigenous population of the Americas and those early pioneers.

However, Naia’s skull, like other examples from the ancient Americas, look very different from the skulls of today’s indigenous people. According to some scientists, this fact indicates that the earliest Americans came from elsewhere.

The discovery of Naia has supplied a critical link. The aforementioned DNA from her molar has a distinctive characteristic that is found in modern indigenous people, particularly from Argentina and Chile. According to researchers, this genetic marker is believed to have originated amongst the people who lived in Beringia.

Another author of the study, Deborah Bolnick of the University of Texas in Austin, has said that this finding does not eradicate the notion that some settlers in ancient times came from elsewhere. What is being suggested, is that there is a clear, undeniable link between those who dwelled in Beringia and the earliest Americans, a well as today’s indigenous populations. The known anatomical differences could simply be a reflection of evolutionary activity.

Despite the fact that the DNA evidence provided by the 12,000 year old molar seems conclusive, some researchers feel that there are still unanswered questions that need to be addressed. Whether by foot or by boat, Naia and the other few skeletal samples from that time period, have provided science with valuable information regarding who first settled the Americas. The search for definitive answers continues.

by Stacy Lamy