image: Cave-diving scientist Patricia A. Beddows of Northwestern University is pictured in the technical SCUBA gear she uses to access the flooded cave systems in Mexico's Yucatán Peninsula. She is a contributing scientist for the Hoyo Negro site, where one of the oldest human skeletons in North America was found alongside at least 16 other animal species. view more
Credit: Credit: E. Monroy-Rios
Cave-diving scientist Patricia A. Beddows of Northwestern University is a member of an international team of researchers and cave divers this week announcing the discovery in an underwater Yucatán Peninsula cave of one of the oldest human skeletons found in North America.
Details of "Naia," a teenage girl who went underground to seek water and fell to her death in a large pit named Hoyo Negro ("black hole" in Spanish), will be published May 16 in the journal Science.
"The preservation of all the bones in this deep water-filled cave is amazing -- the bones are beautifully laid out," said Beddows, who has hovered underwater above the skeleton's site and prospected in the area. "The girl's skeleton is exceptionally complete because of the environment in which she died -- she ended up in the right water and in a quiet place without any soil. Her pristine preservation enabled our team to extract enough DNA to determine her shared genetic code with modern Native Americans."
Beddows, a native of Canada fluent in English, Spanish and French, is available to talk to reporters under embargo and can discuss her experience as one of the two cave-diving scientists who have been underwater at the site. She also can share her expertise on the formation of the caves, the distribution and movement of groundwater at Hoyo Negro and sediments at the site and on the skeleton.
Beddows can be reached at office 847-491-7460, cell 224-420-0977 or patricia@earth.northwestern.edu.
Now covered by water, the girl's skeleton is between 13,000 and 12,000 years old and establishes a shared ancestry between the earliest Americans and modern Native Americans. Genetic analysis shows the prehistoric girl and living Native Americans came from the same place during the initial peopling of the Americas. The near-complete human skeleton -- with an intact cranium and preserved DNA -- was discovered lying 130 feet below sea level near a variety of extinct animals, including an elephant-like creature called a gomphothere. These remains helped scientists establish the age of the skeleton.
Led by Pilar Luna of the Mexican government's National Institute of Anthropology and History (INAH) and James Chatters of Applied Paleoscience, 15 experts from a wide range of fields have been focused on telling the story of the young woman and Hoyo Negro since the skeleton's discovery in 2011.
Beddows' expertise regarding the Hoyo Negro discovery is focused on three areas:
- Cave formation. "Hoyo Negro is a very complex site," Beddows said. "By understanding the formation of the shallow caves and the shaft into which the girl fell, we know that the girl and the animals visited a site that looks almost like it does today, except that the water level was down in the bottom of the shaft."
- Hydrogeology. Beddows' studies starting in the mid-1990s have shown how these extensive caves effectively drain groundwater to the coasts and, more specifically, how the water level in the caves matches sea level very closely. "Using this knowledge, we understand how Hoyo Negro has changed over thousands of years," Beddows said.
- Recrystalized rock sediments. The rocks and the skeletons in Hoyo Negro have valuable rock crystals lying on them, including a new form of impressive crystal growing on them that Beddows calls "florets," in recognition of their bushy nature and one-inch size. "An impressive aspect of this research is that we have dated the skeleton directly, but we also have supported these dates with additional dates on the florets," Beddows said.
Her research focuses specifically on cave systems that are carved by dissolution of soluble carbonate rocks like limestone and dolomite, and her biggest research concentration is the flooded caves of the Yucatán Peninsula, including Hoyo Negro.
"Research in flooded caves is much like space exploration, with divers similar to astronauts reporting back to 'mission control' -- a much larger scientific team at the surface," Beddows said. "It all has to be done on SCUBA, which is our life support system. Our science team has been supported by a great number of dedicated non-science cave divers who have committed hundreds of hours at very dangerous depths to complete this exploration."
Beddows is assistant chair and assistant professor of instruction in the department of Earth and planetary sciences in Northwestern's Weinberg College of Arts and Sciences.
The National Geographic Society supported the research. Its embargoed press release is available in the SciPak package or by contacting press officer Claire Jones at (202) 857-7756 or cgjones@ngs.org.
Journal
Science