The voyage to America

Posted 4 April 2008

Through comprehensive genetic detective work, an international team of researchers led by our Professor Eske Willerslev shows that the ancestors of the North American Indians who came from Asia were the first people in America, and that they were of neither European, African nor other descent, as previously suggested. Willerslev’s team also shows that immigration to North America took place approximately 1,000 years earlier than originally assumed. These findings call for a revision of our understanding of the early immigration route to the American continent. The findings are to be published Express on Friday, 4 April 2008 in the internationally recognised American journal Science.

Fossilised human faeces

Professor Eske Willerslev was surprised by the results of the DNA tests conducted by himself and his colleagues on samples of what turned out to be fossilised human faeces found in deep caves in the Oregon desert. The oldest of the droppings have been carbon-dated to be approximately 14,340 years old. Willerslev’s faeces samples clearly contain two main genetic types of Asian origin that are unique to present-day North American Indians. Not only is this proof that the American Indians are descendants of the first immigrants to the continent, it is also proof that immigration took place approximately 1,000 years earlier than otherwise believed.

Questions old theories

The American continent was the last of the world’s continents to be populated. There are many contradictory and more or less well-founded scientific theories on when this occurred and from where the first immigrants came. These theories span from immigration via the icy Atlantic Ocean to Thor Heyerdahl’s papyrus boat expeditions from Africa to America.

The most accepted theory is based on findings of stone tools from the Clovis culture in soil layers dating back to approximately 13,000 BC. According to the theory, people from Siberia migrated, perhaps in search of mammoth, across the land bridge that once connected Siberia and North America. From there, they continued south and spread out across the American continent. The migration passed through a corridor that opened up approximately 14,000 years ago in the giant glacier that covered the American continent.

But these new findings call this immigration theory into question. “Our findings show that there were people south of the ice cap several hundred years before the ice-free corridor developed. The first humans either had to walk or sail along the American west coast to get around the ice cap,” explains Eske Willerslev, and concludes, “That is, unless they arrived so long before the last ice age that the land passage wasn’t yet blocked by ice.”