Central to the
peopling of the Americas was the coastal migration along the Pacific
littoral. This placed the Bering genome from
one end to the other of the Americas. It
also happened quickly as well. I also
suspect that it happened earlier that 13,000 BP, but may also have happened
twice after the effects of the Pleistocene Nonconformity around 12900 BP.
Inland migration
took a lot longer and surely ran into similar peoples coming off the Atlantic
Seaboard. Inland peoples had to master
their local biome and that always takes a long time. It is also naturally one long step at a time
and did not catch fire until the corn culture was invented.
In the meantime
we have this wonderful skeleton that is an incredible 13,000 years old.
Prehistoric
girl's bones in underwater cave helps link ancient and native Americans
By Sheryl Ubelacker,
In this June 2013 photo
provided by National Geographic, divers Alberto Nava and …
TORONTO - 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.
"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.
Chatters, the first scientist to study the prehistoric skeleton
known as Kennewick Man that was found in Washington state in 1996, described
Hoyo Negro as being like a miniature of California's La Brea tar pits,
"only without the tar and with considerably better preservation."
At the time of Naia's death, the caves would have been dry and
accessible, he told a media teleconference. "Perhaps seeking fresh water
in the dark passages, animals and at least one human fell into this inescapable
... 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. In a 50-metre-deep sinkhole within the
cavern, the girl's skull was resting on a boulder, "laying upside-down
with a perfect set of teeth and dark eye sockets looking back at us," said
diver Alberto Nava.
After the divers reported their find to the National Institute of
Anthropology and History in Mexico, a consortium of 16 scientists and cave
explorers from Mexico, the U.S. and Canada was formed in 2011 to photograph and
document the site, and to collect fossilized flora and fauna samples for
testing.
"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 McMaster 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.
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.
Whether all early inhabitants of the Americas came across the
Bering land bridge or somehow migrated from elsewhere in the world remains a
controversial question because of the differences in skull shape and facial
features among prehistoric fossilized remains discovered across the Americas
and modern-day indigenous populations.
Naia's skull shape and facial features are considered
"Paleoamerican" and differ from native Americans living today in the
Western Hemisphere.
"Because she exhibits the distinctive Paleoamerican skull and
facial features, the study shows for the first time that Paleoamericans with
these distinctive features can have Beringian ancestry," said Deborah
Bolnick, a genomic anthropologist at the University of Texas at Austin.
Bolnick said the physical differences between them are likely due
to evolutionary changes that occurred either in Beringia or in the Americas
over the last 9,000 years, rather than the two groups having separate origins.
"Mitochondrial DNA for this individual does not exclude the
possibility of separate ancestry for some Paleoamericans, but our results
provide no evidence for an early migration to the Americas from other regions
of the world — southeast Asia, Australia or Europe — as some have
proposed," she said.
"Instead, our results suggest that Paleoamericans and
contemporary native Americans both have Beringian ancestry."
Reinhardt of McMaster said Hoyo Negro, which is now off-limits to
the public because unauthorized divers have disturbed the artifacts, said the
cathedral-like site is breathtakingly beautiful, with crystal-clear water
surrounded by white limestone walls.
But for Naia, who may have been seeking fresh water in the cavern
and accidentally plunged into the sinkhole and could find no escape, it must
have been a terrifying experience, he said.
"When we're diving the site, it's spectacular, but the
reality is this pit was a bit of a house of horrors in the sense that you would
drop and perhaps survive the fall but not have any light. You wouldn't know the
extent of the cavern. You'd be in a pool of water (at the bottom), kind of
thrashing around trying to get out.
"Yeah, it would have been a pretty awful way to die for
sure."
Follow @SherylUbelacker on
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