Mystery of the Bog Bodies

Early in May 1950, a family in Denmark was digging for a material called peat, which is made of decomposed plants that can be burned as fuel. As they dug, they uncovered quite a surprise: a human body. It was a man, curled up on his side with a leather rope around his neck and a strangely peaceful expression on his face.

Fearing he was a murder victim, the family called the police. They explained that they’d found the body about 2.5 meters (8 feet) underground and that they’d seen no signs of recent digging. The police quickly realized this was no typical criminal investigation—they were dealing with an ancient mystery.

In early May 1950, a family in Denmark was digging for peat. This material is made of decayed plants, and it can be burned as fuel. The family dug up quite a surprise. It was a human body. The man was curled up on his side, with a leather rope around his neck. He had a strangely peaceful look on his face.

The family feared he was a murder victim, so they called the police. They explained that they’d found the body about 2.5 meters (8 feet) underground. But they’d seen no signs of recent digging. The police soon realized this was no everyday criminal investigation. They had an ancient mystery on their hands.

Police officers and curators from the nearby Silkeborg Museum visited the site together. They called in an archaeologist to excavate the remains. The dead man was given the nickname Tollund Man in honor of a nearby village. His body was so well preserved it looked as though he had died just recently. But in fact, Tollund Man was 2,400 years old!

In the nearly 70 years since his discovery, Tollund Man has led a busy afterlife, as scientists work to piece together who he was and how he died. And he’s not alone: Hundreds of naturally mummified human remains have been found in bogs—marshy areas that accumulate peat—across Europe (see Uncovering Bog Bodies). Many of these bog bodies show evidence of violent deaths. After years of study, these eerie, ancient people are slowly beginning to reveal their secrets.

Police officers visited the site. Curators from the nearby Silkeborg Museum came with them. They called in an archaeologist to dig up the body. The dead man was nicknamed Tollund Man after a nearby village. His body was so well preserved it looked like he had died recently. But Tollund Man was 2,400 years old!

Almost 70 years have passed since his discovery. Tollund Man has led a busy afterlife, as scientists work to learn who he was and how he died. And he’s not alone. Across Europe, hundreds of naturally mummified human bodies have been found in bogs. These are marshy areas where peat builds up (see Uncovering Bog Bodies). Many of these bog bodies show signs of violent deaths. Scientists have studied them for years. And these eerie, ancient people are slowly starting to reveal their secrets. 

The bog where Tollund Man was discovered is a flat, barren expanse of land covered by brown mats of moss called sphagnum (see What Makes a Bog). Bogs are different from other types of wetlands. Bog water has low levels of nutrients and oxygen. It’s also acidic. Unlike most other plants, sphagnum is able to thrive in these conditions.

The low oxygen and high acidity make bogs fantastic at naturally preserving human remains in astonishing detail. Bogs are inhospitable to many bacteria, fungi, and insects that normally break down organic matter—like bodies. The acidic waters are especially good at preserving soft tissues, like skin and internal organs, in the same way that vinegar can pickle vegetables.

The bog where Tollund Man was found is a flat, open space. It’s covered by brown mats of moss called sphagnum (see What Makes a Bog). Bogs are different from other types of wetlands. Bog water has low levels of nutrients and oxygen. It’s also acidic. Most plants can’t thrive in these conditions. But sphagnum does.

Bogs are fantastic at preserving human bodies in great detail. That’s because of their low oxygen and high acidity. These conditions keep out many bacteria, fungi, and insects that digest and break down organic matter—like bodies. The acidic waters are great at preserving soft tissues, like skin and internal organs. It’s the same way that vinegar pickles and preserves vegetables. 

Recently, scientists at the Natural History Museum of Denmark took samples from the mummy’s thighbone and abdominal skin and attempted to extract DNA. They wanted to compare his genetic material to samples from other Iron Age remains. “The idea was to try to learn where he came from. Was he a local guy or a migrant from somewhere else?” says Morten Allentoft, a geneticist at the museum.

Recently, scientists at the Natural History Museum of Denmark took samples from the mummy’s thighbone and the skin on his abdomen. Then they tried to extract DNA. They wanted to compare his genetic material to samples from other Iron Age remains. “The idea was to try to learn where he came from. Was he a local guy or a migrant from somewhere else?” says Morten Allentoft. He’s a geneticist at the museum. 

Unfortunately, the acids that make bogs great at preserving soft tissue tend to destroy DNA. Tollund Man’s genetic material was hopelessly fragmented, and scientists were unable to piece it together. Curators have thought about sampling DNA from the densest bone in the human skeleton, near the base of his skull, where DNA might be better protected. But for now they want to avoid drilling into Tollund Man’s almost perfectly preserved head.

Scientists at the National Museum of Denmark also recently analyzed isotopes—atoms of the same chemical element with different masses—of strontium (Sr) in Tollund Man’s hair and thighbone. Strontium occurs in different concentrations in various regions of the world. People absorb strontium from local food and water, and the element accumulates in their bones and hair. Results suggest Tollund Man spent his final year around Silkeborg and had traveled at least 40 kilometers (25 miles) away at some point in his last 10 years of life.

The acids in bogs preserve soft tissue, but they tend to destroy DNA. Tollund Man’s genetic material was broken into many pieces. Scientists couldn’t put it together. Curators have thought about taking DNA from the densest human bone, where DNA might be protected better. That’s near the base of the skull. But Tollund Man’s head is almost perfectly preserved. For now, they don’t want to drill into it.

Scientists at the National Museum of Denmark recently studied clues in Tollund Man’s hair and thighbone. They looked at isotopes of strontium (Sr). Isotopes are atoms of the same chemical element with different masses. Strontium is found in different amounts in different places. People take in strontium from local food and water, and the element builds up in their bones and hair. Results suggest Tollund Man spent his final year around Silkeborg. And he traveled at least 40 kilometers (25 miles) away sometime in his last 10 years of life.

In 2002, Tollund Man journeyed from his home at the Silkeborg Museum to a hospital in nearby Aarhus for CT scans. The scans use X-rays to create 3-D images of a body’s insides. They allowed museum curators to create digital replicas of the mummy’s face, skull, and feet for further study.

In 2002, Tollund Man traveled from the Silkeborg Museum. He went to a hospital in nearby Aarhus for CT scans. The scans use X-rays to make 3-D images of a body’s insides. Museum curators used them to create digital copies of the mummy’s face, skull, and feet for more study.