Thanks to a detailed analysis of ancient DNA, archaeologists have revealed the settlement history of the Arctic's earliest people, a new study describes.

People have lived in the New World Arctic for about 5,000 years, braving the harsh climate conditions in places like Alaska, Canada and Greenland. But until now, scientists had long been puzzled over the ebb and flow of these different ancient groups, and who truly were the region's first settlers.

Described in the journal Science, researchers show that the Paleo-Eskimo, who lived in the Arctic from about 5,000 years ago until about 700 years ago, represented a distinct wave of migration from other Arctic inhabitants. They also found that these people are genetically separate from today's Inuit and Native Americans of the Arctic.

"Our genetic studies show that, in reality, the Paleo-Eskimos - representing one single group - were the first people in the Arctic, and they survived without outside contact for over 4,000 years," lead author Eske Willerslev, of the University of Copenhagen, said in a press release.

Inuit hunters in the Canadian Arctic have long told stories about a mysterious ancient people known as the Tunit, who once inhabited the far north. According to these myths they were giants, who were taller and stronger than the Inuit, but easily frightened from their settlements by the newcomers.

Many scientists simply dismissed these tales as pure fiction, but the new study suggests they may not be so far off base.

Willerslev and molecular biologist Maanasa Raghavan, along with colleagues, revealed for the first time that the Paleo-Eskimos indeed did live in isolation from their neighbors, refraining from mixing with any other groups of people.

"Elsewhere, as soon as people meet each other, they have sex," Willerslev told National Geographic. "Even potentially different species like Neanderthals [and modern humans] had sex, so this finding is extremely surprising."

Moreover, the team's DNA analysis revealed that the Paleo-Eskimos disappeared around 700 years ago - around the time that technologically superior ancient Inuits came onto the scene.

This study is the first to solve some age-old questions about the New World Arctic, the region's first inhabitants, and its migration history.