This month, a Western Michigan University bio-anthropologist was featured on the PBS show NOVA, in an episode called “Secrets of the Sky Tombs.” Jacqueline Eng studies ancient cliff-side tombs in Nepal. By looking at the bones and teeth, Eng and other anthropologists are trying to find out more about the health and cultural heritage of the people buried there.
The country of Nepal is in the Himalaya Mountains, between India and Tibet. Because of the high altitude it’s already a difficult place to live.
“High mountain areas are one of the last places that people migrated to to settle permanently," says Eng. "You know people may have passed through to reach another destination that had fertile area for a pasture or agriculture, but eking out an existence at high altitude is quite difficult.”
Eng says when she first visited in 2010, she thought she was prepared for the high elevation.
“I read things and I was staying hydrated. I thought I was relatively fit. But then once you start moving and you feel that sluggishness, and you feel that tiredness because you can’t sleep through the night. It was a bit humbling as you’re trying to walk up the hill and you’ve got villagers going along with flip flops and maybe - as you see - carrying lumber on their heads and they’re moving faster than you are.”
Getting to the tombs themselves is even harder. They’re so high up on the cliff that trained climbers had to collect the bones from the caves and lower them down to the anthropologists. Though they’re difficult to reach, Eng says the bones in the cliffs are really well preserved:
“Because it’s so extreme in terms of the environment. So anytime an environment is extreme - whether it’s really cold, really hot, really wet or really dry - then that helps with the preservation of remains because of course bones and tissue, that’s got organic materials. And so in this situation it’s very cold and it’s very dry.”
I know what you’re thinking: If the caves are so high up, why did people bury the bones there in the first place? Two reasons. First, what’s now a cliff didn’t used to be a cliff at all. It was more like a hilltop cemetery.
“They had dug a shaft tomb into that high hillside, and it was because of some tectonic activity that the face of the cliff had fallen - and that’s where we’re seeing some bones," says Eng. "So actually there was only openings on top that may have been sealed, but in the past it hasn’t been exposed as a cave.”
Second, it was part of their culture. Most of the villagers near the cave - in Samdzong, Nepal - practice Buddhism. Eng says often Buddhists cremate their dead, but in mountain regions like this there aren’t enough trees to make a big enough fire.
So instead some Buddhists do what’s called a sky burial. Eng says that’s where the body is picked clean by vultures or other birds of prey, then the bones are ground down to small shards.
“The thinking is that it helps with the reincarnation - and you know you’re giving back to nature. In this instance birds are incorporating these remains and it helps with reincarnation. And whether or not these remains in Samdzong - which had evidence of the cuts on the bones which were areas where you would dismember and disarticulate…so there’s dismemberment and de-fleshing - whether that preceded the Buddhist ritual of sky burial in the region, that’s what we’re analyzing. Hopefully we get more remains and see this kind of pattern.”
Anthropologists also found a carving of the Buddha that is much older than they expected. Eng (Ing) says that might mean that Buddhism was introduced in the area a lot earlier - possibly through trade.
“It certainly could be from a traveler because we have signs of an extensive trade network from throughout Asia. Cause we have the evidence of glass beads which come from southern Asia and you have some other artifacts that have some ties to the area where modern Iran is, and then silk from China. And we know that just further north you have these silk trade routes.”
Because anthropologists saw artifacts from multiple cultures in the caves, it was difficult to say where these ancient peoples migrated from. At first, they thought they came from the south because many of the items in the cliffs were from what’s now India - but DNA from their bones told a different story.
“The sequences of people in the caves in Nepal seemed to match those to the east side of Asia, so links to China, Japan, Tibet and the Sherpas. So it’s looking like migration actually had occurred from the north, north east rather, through the Himalayas from people who are living in east Asia.”
What’s even more interesting - anthropologists discovered the ancient peoples had two types of genes to keep them from getting altitude sickness. Eng says the first one is more common around the world.
“But then there seems to be specific ones that’s just in the Tibetan people. And what’s really fascinating is that sequence seems to have been something that was introduced by another Hominin species that was mentioned that comes from Siberia in the Altai region.”
In other words, a gene from a different species of human from the largest province in what’s now Russia. Eng says the history of the people buried in these cliffs shows how adaptable humans can be over time.
Unfortunately the cliffs are eroding away. Eng says it’s in an area where the Earth’s tectonic plates shift underground, causing huge chunks of the cliffs to fall into the Kali Gandaki River. Flooding in Nepal doesn’t help either.
“When the monsoon season comes the river can get quite high. So any bones that are eroding off would just be carried away by the Kali Gandaki. And we don’t know how many have been lost through the waters. And so that’s one of the reasons why it was considered rescue archeology because the bones were eroding and again in time they were falling and they would be washed away by the next season.”
Eng says her team will continue to research the tombs to try to discover more about these ancient peoples. She says it’s fascinating to find out how they survived in such a harsh climate and how the people of Nepal manage today:
“It’s just amazing that distance wise it isn’t that far between villages, but it does sometimes take a day or two to go between areas. And so you can imagine how long it took for people to do trade or to communicate and exchange ideas and interact. People would go, for instance, for the horse festival. And it just gives you an appreciation of community.”
Jacqueline Eng is a bio-anthropologist at Western and was featured on an episode of NOVA called “Secrets of the Sky Tombs.” The video will only be available for a limited time.
