A 12,000 year-old skeleton discovered in an underwater cave may reveal how the first humans arrived in the New World.
The cave where the remains were found lies under the Yucatán Jungle in Mexico. It stretches 200 feet in length, and is 130 feet wide. This area was discovered in 2007 by divers who entered a sinkhole in the Yucatán, which led to a network of tunnels. The adventurers swam through one tunnel for half a mile before the path opened up, revealing the sizable cave.
A skull, belonging to a small-framed teenaged female was discovered in the subterranean caves. Researchers believe the girl fell to her death, 120 centuries ago. Remains of other animals were found near the young woman, including giant ground sloths, saber-tooth cats, and cave bears.
The young woman has, unofficially, been given the name Naia. At the time she lived in the area, the network of caves was not flooded, containing just small quantities of water. This may have been what drew Naia to the tunnels. Analysis of the remains suggests she was 14 or 15 years old, and stood four-foot-ten. Evidence suggests she slipped and fell into the lower cave, where she broke her hip, and later died.
Melting glaciers at the end of the last ice age filled the tunnels with water. Since that time, the caves have been below sea level.
"The moment we entered inside, we knew it was an incredible place. The floor disappeared under us and we could not see across to the other side. We plunged a way down inside. All we could see was darkness," Alberto Nava, one of the divers who discovered the caves, told reporters.
Analysis of the skeletal remains suggests Naia lived somewhere between 12,000 and 13,000 years ago.
Paleontologists are debating the origins of the first humans in the new world. Ancient remains show the existence of paleoamericans, who possessed significant physical differences to modern Native Americans. Some researchers believe these people may have come to the Americas from Southeast Asia, Australia or Europe.
Native Americans are believed to have originated from a stock of people who lived in Beringia, located between modern-day Alaska and Russia. This land washed away thousands of years ago, long after the settlers moved east and south, into the New World.
Analysis was performed on mitochondrial DNA extracted from the girl's wisdom tooth. This revealed she was descended from an Asian genetic lineage that is only present in Native Americans. This provided the first direct fossil evidence linking the two groups.
Study of Naia and how her unfortunate death could help us answer questions about the first people in the Americas, was profiled in the journal Science.
