The great global migration of
early humans out of Africa went further and higher than previously thought
according to two sets of discoveries which suggest that the inhabitants of
Easter Island in the Pacific had contact with the people of South America, who
in turn had established the highest Stone Age
settlement in the world.
The long and controversial debate
over whether the early Polynesians managed to completely cross the Pacific
Ocean and land in the Americas is supported by a genetics study of the indigenous Easter Islanders, which
found that they share DNA sequences with Native Americans – suggesting close
contact between the two populations.
Meanwhile in a separate study,
archaeologists working in the southern Peruvian Andes have unearthed the
remains of an early human settlement nearly 4,500 metres (15,000ft) above sea
level, which would have been at the physical limits of surviving and for women to
bear children, scientists said.
The archaeologists estimate that
the settlement, which includes a stone shelter decorated with rock art, was
occupied about 12,000 years ago, within about 2,000 years of the first humans
arriving in South America from Central and North America.
Living at such a high altitude
would have been difficult because of the cold temperatures, high solar
radiation and low oxygen concentrations, but the evidence, which included stone
tools used for butchering animals, suggested that the site was occupied for
long periods of time.
“We don’t know if people were
living there year-round, but we strongly suspect they were not just going there
to hunt for a few days, then leaving. There were possibly even families living
at these sites, because we’ve found evidence of a whole range of activities,”
said Sonia Zarrillo of the University of Calgary in Canada, one of the authors
of the study published in the journal Science.
While it is accepted that the
Americas were first colonised by people crossing from Asia on a land bridge to
Alaska, some scientists have suggested that there was a second colonisation
from the east by Polynesians who had experience of sailing long distances in
double-hulled canoes.
Two further studies, published in
the journal Current Biology, lends support to this controversial hypothesis by
discovering genetic links between the native inhabitants of Rapanui – Easter
Island – and the indigenous people of South America. This suggests there was
contact and interbreeding between the remote Pacific island and the American
mainland long before the arrival of the first Europeans.
Anna-Sapfo Malaspinas of the
Natural History Museum of Denmark, and colleagues, analysed the DNA of 27
native Rapanui people and found that their genomes on average were about 76 per
cent Polynesia, eight per cent Native American and 16 per cent European.
However, further analysis showed
that although the European lineage could be explained by contact with white
Europeans after the island was “discovered” in 1722 by Dutch sailors, the South
American component was much older, dating to between about 1280 and 1495, soon
after the island was first colonised by Polynesians in around 1200.
This suggested that either South
American Natives had sailed west to Rapanui or that the Rapanui has continued
to sail east to South America, and then somehow made the return journey back to
the island, nearly 2,500 miles away.
“All sailing voyages heading
intentionally east from Rapa Nui would always reach the Americas with a trip
lasting two weeks to approximately two months. The return trip appears more
challenging,” the scientists said.
Although the latter journey was
more difficult, it could also explain why the sweet potato – a native plant of
South America – had been grown and eaten across Polynesia long before the first
Europeans arrived, they said.
In yet another study, Professor
Eske Willerslev of the Natural History Museum in Denmark found that the DNA of
two ancient skulls found in Brazil – from the indignenous “Botocudos” natives –
have a distinct Polynesian ancestry, with no DNA sequences that can be
described as unique to Native Americans.
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