Dna and radio carbon dating
Hoyo Negro is an underwater cave in Mexico's Yucatan Peninsula where archeologists found the remains of sabre-tooth tigers, giant ground sloths, cave bears and a teenage girl named "Naia." (Roberto Chavez Arce via Science/Associated Press) The pristine skeleton of a teenaged girl who lived about 13,000 years ago, discovered in a deep, water-filled underground cavern in the sprawling cave system in Mexico's Yucatan Peninsula, is providing archeologists with an unprecedented glimpse into the history of the early inhabitants of the Americas.
Given the name Naia, Greek for "water nymph," the remains of the 15- or 16-year-old girl were found at the bottom of the boulder-strewn, underwater chamber dubbed Hoyo Negro — "black hole" in Spanish — along with the scattered bones of 26 large animal species, among them sabre-tooth tigers, giant ground sloths and cave bears.
"A big part of it has just been trying to map the locations of things and get the shape of the tunnels and cavern, and mapping locations of human bones and animal bones," said Ed Reinhardt, a professor of geography and earth sciences at Mc Master University in Hamilton who is part of the research team.
His role is studying microfossils, such as those of single-celled animals, and water salinity, within Hoyo Negro.
"Sealed off by water and darkness for over 8,000 years, it is a time capsule of the environment and human life in central America at the end of the Ice Age, when glaciers across the globe trapped massive amounts of water as ice and sea level was far lower than it is today," said American paleontologist Jim Chatters, head of an international research team investigating the site and its archeological treasures.
trap." Naia's remains were discovered in 2007 by three Mexican cave divers exploring an underwater cavern, deep in the Yucatan jungle about eight kilometres from the Caribbean coast.But beyond the stunning discovery of Naia's skeletal remains in her watery grave, reported Thursday in the journal Science, is what DNA from her bones is telling researchers about the origins of the Western Hemisphere's first peoples and their link to modern-day native Americans.Based on carbon-dating and other chronology testing, the researchers estimate "the small, slight" girl lived between 12,000 and 13,000 years ago.DNA was extracted from one of Naia's teeth and scientists sequenced what's called mitochondrial DNA, which is passed from mother to child.
The results show the girl is related, maternally at least, to today's native Americans, meaning both would trace their lineage to Beringia — the land masses on either side of the ancient land bridge now covered by the Bering Sea that was used by prehistoric people to migrate from northeast Asia into what is now Alaska and southward into Central and South America.Those first migrants have been dubbed the Clovis people.