Revealing the past’s
secrets
Girl’s 12,000-year-old skeleton may solve
mysteries of the origins of earliest Americans
by joel achenbach
T
he divers found her on a ledge,
her skull at rest on an arm
bone. Ribs and a broken pelvis
lay nearby. She was only 15
years old when she wandered into the
cave, perhaps in search of water in an
era when the Yucatan was parched. In
the darkness she must not have seen
the enormous pit looming in front
of her.
More than 12,000 years later, in
2007, after the seas had risen and the
cave system had filled with water, her
skull — upside down, teeth remarkably
intact — caught the eye of a man in
scuba gear.
The divers gave the girl a name:
Naia. Her remains may help determine
the origins of the earliest Americans
and finally solve the mystery of why
they looked so dramatically different
from the Native Americans of recent
millennia.
A paper published online in the journal Science argues that the discrepancy
in appearance between the Paleoamericans and later Native Americans is
most likely the result of recent, and
relatively rapid, human evolution —
and not the result of subsequent migrations of people into the Americas.
Tests on samples of mitochondrial
DNA taken from Naia show that she
has a genetic marker common today
across the Americas, one that scientists
say evolved in a prehistoric population
that had been isolated for thousands
of years in Beringia, the land mass
- the washington post
between Alaska and Siberia that formed
a bridge between the continents during
the Ice Ages.
Thus, according to the new report,
the Native Americans and the Paleoamericans are the same people; they
just look different because of evolutionary changes.
“This is truly an extraordinary
discovery,” said Yemane Asmerom, a
University of New Mexico geochemist
who is a co-author of the new report.
He compared the cave, known as Hoyo
Negro (“black hole”), to the Awash
Valley of Ethiopia — the site of the
1974 discovery of “Lucy,” an early human ancestor.
Most scientists have assumed that the
first humans to come to the Americas
crossed over from Eurasia across the
Bering land bridge that existed before
the oceans rose after the Ice Ages. But
there is great debate about whether this
represented a single migratory event or
multiple pulses of people from different parts of Eurasia and via different
routes, including a coastal migration.
One maverick theory, based on archeological finds, contends that people
came from Europe, following the edge
of the ice around the North Atlantic.
Adding to the mystery is that the
Paleoamericans, such as Naia, don’t
look like later Native Americans. Naia
had a small, projecting face, with narrow cheekbones, wide-set eyes and a
prominent forehead. Her profile would
resemble that of an African more than
a Native American, said James Chatters, an independent researcher based
in Washington state and the lead author
of the new paper.
This distinct morphology is most
famously found in the “Kennewick
Man,” a 9,000-year-old skeleton discovered two decades ago along the Columbia River in Washington state. Facial
reconstruction resulted in someone
who looked a bit like the actor Patrick
Stewart (“Star Trek,” “The X-Men”).
Scientists theorized that he could have
been related to populations in East
Asia that spread along the coast and
eventually colonized Polynesia; modern
Native Americans may have descended
from a separate migratory population,
under that scenario.
Chatters said in an interview, “For
20 years I’ve been trying to understand
why the early people looked different.
The morphology of the later people
is so different from the early ones that
they don’t appear to be part of the
same population.”
He went on: “Do they come from
different parts of the world? This
comes back with the answer, probably
not.”
One of the co-authors of the paper,
Deborah Bolnick, an anthropologist
at the University of Texas at Austin,
said the new genetic tests support the
hypothesis of a single ancestral population for Native Americans: “It’s a
See SKELETON, Page 10
Spring 2014
Research Texas
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