New genetic data
from ancient bones suggests a wave of South American seafarers wreaked
havoc on Caribbean islanders.
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Caribbean traders approach
an island in the Bahamas, part of an ancient exchange network
that knit the islands together before the arrival of the Spanish.
PAINTING BY MERALD CLARK, STONE INTERCHANGES IN THE BAHAMA
ARCHIPELAGO
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SPANNING A MILLION square miles and dotted with more than 700 islands,
the Caribbean Sea was one of the last places colonized by Native
Americans as they explored and settled North and South America.
Archaeologists have long struggled to pinpoint the origins and movements
of those intrepid seafarers. Now, thanks to genetic material gleaned
from the bones of ancient Caribbean residents, the invisible history
of this tropical archipelago is coming to light.
Among the surprising findings is that most of the Caribbean's original
inhabitants may have been wiped out by South American newcomers
a thousand years before the Spanish invasion that began in 1492.
Moreover, indigenous populations of islands like Puerto Rico and
Hispaniola were likely far smaller at the time of the Spanish arrival
than previously thought.
Extracting DNA from bones in warm, wet places like the Caribbean
was impossible until a few years ago. But thanks to recent advances
in genetic technology, a Harvard University lab run by geneticist
David Reich was able
to recover DNA from 174 individuals excavated at sites from Venezuela
to the Bahamas.
The results,
published December 23 in the journal Nature, follow on the
heels of a July paper
in Science that analyzed the genomes of 93 ancient Caribbean
individuals at a University of Copenhagen lab. Because of the breakthrough,
"we are able to paint a very detailed picture of the early migration
history of the Caribbean," said Johannes
Krause, director of the Max
Planck Institute for the Science of Human History and a co-author
of the Science paper.
Both studies confirm that a wave of pottery-making farmersknown
as Ceramic Age peopleset out in canoes from the northeastern
coast of South America starting some 2,500 years ago and island-hopped
across the Caribbean. They were not, however, the first colonizers.
On many islands they encountered a foraging people who arrived some
6,000 or 7,000 years ago from the coasts of Central America and
northern South America.
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Pottery-making farmers
first came to the Caribbean from South America some 2,500
years ago, largely replacing the islands' earlier inhabitants,
who lived by foraging. The pottery makersknown as Ceramic
Age peoplealso continued to make and use stone tools
similar to those used by earlier Archaic Age foragers.
PHOTOGRAPH BY KRISTEN GRACE, FLORIDA MUSEUM
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The foragersknown as Archaic Age peopleseem to have
largely vanished soon after the newcomers appeared. There are only
limited genetic traces of Archaic individuals in the Ceramic Age
people, a sign that the two groups rarely mixed. The ceramicists,
who are related to today's Arawak-speaking peoples, supplanted the
earlier foraging inhabitantspresumably through disease or
violenceas they settled new islands.
But there are intriguing exceptions that paint a more complex picture
of the interactions between these two distinct peoples.
"The remarkable thing is that the Archaic way of life seems to
survive in western Cuba until about 900 C.E.," said William
Keegan, an archaeologist at the Florida Museum of Natural History
and a co-author of the Nature study. "They apparently lived
unmolested and with little mixing."
Provocative discovery
One of the most provocative findings of the Harvard study is that
the indigenous populations of large islands like Puerto Rico and
Hispaniola were far smaller at the time of the Spanish arrival than
Spanish records suggested.
A decade after Columbus arrived, a Spanish friar estimated that
there were as many as 3.5 million people on Hispaniola, today's
Haiti and Dominican Republic. But extrapolations from the genetic
data, based on new mathematical models, point to only tens of thousands
of inhabitants. That calls into question the old assumption that
hundreds of thousands, if not millions, of indigenous people died
from disease and other impacts of the European invasion.
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The Harvard study was
based on DNA recovered from the skeletal remains of 174 individuals,
including this Lucayan woman who lived in the Bahamas in the
1300s. The Lucayan people practiced cranial flattening, as
indicated by the shape of her skull.
PHOTOGRAPH COURTESY WILLIAM F. KEEGAN, FLORIDA MUSEUM
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"This new approach of estimating past population sizes has the
potential to revolutionize our view of past migration and cultural
changes," said Krause.
While large numbers of indigenous people died after the arrival
of the Spanish, genetic studies show that their DNA survives in
modern-day islanders, mixed with genes from later European colonizers
and enslaved Africans.
Many indigenous groups have alleged that geneticistsoften
white Europeans and Americansdon't consult with them, or show
proper respect for their traditions, while investigating their origins.
In this case, however, the Nature authors said they collaborated
with descendant communities as well as local Caribbean scholars
in gathering and analyzing their data. The research was supported
in part by a grant from the National
Geographic Society.
Making connections
One mystery yet to be resolved is how relatively small island populations
avoided inbreeding over so many centuries. There is no sign of any
subsequent major migrations from the mainland. But archaeologists
say the new evidence points to extensive island-to-island contacts
that likely helped ensure genetic diversity.
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Archaeologist Michael
Pateman and local resident Anthony Maillis begin excavating
a dune on Long Island in the Bahamas. A 2015 hurricane eroded
the dune and exposed human bones, which Maillis and his companions
spotted and reported to authorities. The dune contained three
ancient burials, included the Lucayan woman (previous photo).
PHOTOGRAPH COURTESY WILLIAM F. KEEGAN, FLORIDA MUSEUM
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The research published in Nature "highlighted the connectivity
of peoples in the region," said Jada
Benn Torres, a Vanderbilt University genetic anthropologist
who was not directly involved in the study. Torres and her colleagues
say a next step is to understand the links among islands in what
remained a relatively closed system until the Spanish arrived in
1492.
"This was a dynamic and interconnected region of the world," said
Miguel
Vilar, a University of Maryland anthropologist. The history
of the Caribbean, he said, "is finally being understood through
DNA in ways that archaeology alone hasn't been able to do before."
Andrew Lawler is a journalist
and author who has written about controversial
excavations under Jerusalem and the search
for the Lost Colony of Roanoke for National Geographic.
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