High in the Indian Himalayas, a remote lake in a snowy valley is filled with hundreds of human skeletons.
Lake Roopkund is located 5,029 meters (16,500 feet) above sea level, at the bottom of a steep slope in Trisul, one of the highest mountains in India, in the state of Uttarakhand.
The remains are scattered around and under the ice in the “skeleton lake”, discovered by a British forestry patrolman in 1942. For more than half a century, anthropologists and scientists have studied the remains.
The lake has attracted scientists and curious visitors for years. Depending on the season and climate, the lake, which remains frozen most of the year, expands and shrinks. Only when the snow melts the skeletons are visible, sometimes with trapped and well-preserved meat. To date, the remains of about 600-800 people have been found here. In tourist promotions, the local government describes it as a “mysterious lake”.
For more than half a century, anthropologists and scientists have studied the remains and were intrigued by a number of questions.
Who were these people? When did they die? How did they die? Where did they come from?
An old theory associates the remains with an Indian king, his wife and his assistants, all of whom died in a blizzard some 870 years ago.
Another suggests that some of the remains are from Indian soldiers who tried to invade Tibet in 1841 and were defeated. More than 70 of them were forced to find their way home in the Himalayas and died on the way.
Yet another assumes that this could have been a “cemetery” where victims of an epidemic were buried. In the villages in the region, there is a popular folk song that talks about how the goddess Nanda Devi created a hail storm “as hard as iron” that killed people who snaked past the lake. India’s second highest mountain, Nanda Devi, is revered as a goddess.
Previous skeleton studies found that most people who died were tall – “above average height”. Most of them were middle-aged adults, aged between 35 and 40 years. There were no babies or children. Some of them were elderly women. Everyone had reasonably good health.
In addition, it was generally assumed that the skeletons were from a single group of people who all died at once in a single catastrophic incident during the 9th century.
The latest five-year study, involving 28 co-authors from 16 institutions based in India, USA and Germany, concluded that all of these assumptions may not be true.
Scientists have genetically analyzed and dated the remains of 38 bodies, including 15 women, found in the lake with carbon – some of them dating back to around 1,200 years.
They found that the dead were genetically diverse and that their deaths were separated in time for up to 1,000 years.
“It gets in the way of any explanation that involves a single catastrophic event that led to their death,” Eadaoin Harney, the study’s lead author and a doctoral student at Harvard University, told me. “It is not yet clear what happened at Lake Roopkund, but now we can be sure that the deaths of these individuals cannot be explained by a single event.”
But the most interesting thing is that the genetic study found that the dead were made up of several people: one group of people had genetics similar to those of current people living in South Asia, while the other “closely related” to people living in Europe current, particularly those living on the Greek island of Crete.
Furthermore, people who came from South Asia “do not appear to be from the same population”.
“Some of them have ancestry that would be more common in groups in the northern subcontinent, while others have ancestry that would be more common in groups further south,” says Ms. Harney.
So, did these diverse groups of people travel to the lake in smaller batches over a period of a few hundred years? Did any of them die during a single event?
No commercial weapons or merchandise were found at the site – the lake is not located on a trade route. Genetic studies have found no evidence of the presence of any ancient bacterial pathogens that could provide the disease as an explanation for the cause of the deaths.
A pilgrimage through the lake may explain why people were traveling in the area. Studies reveal that credible reports of pilgrimage in the area do not appear until the end of the 19th century, but inscriptions in local temples date back to the 8th and 10th centuries, “suggesting potential earlier origins”.
Thus, scientists believe that some of the bodies found at the site occurred because of a “mass death during a pilgrimage event”.
But how did people in the eastern Mediterranean land on a remote lake in India’s highest mountains?
It seems unlikely that people from Europe traveled from Roopkund to participate in a Hindu pilgrimage.
Or was it a genetically isolated population of people with distant ancestors from the eastern Mediterranean who have lived in the region for many generations?
“We are still looking for answers,” says Ms. Harney.