Peruvian Ice Maiden

The Peruvian Ice Maiden is a 500-year-old mummy that was discovered in the Peruvian Andes in 1995. She is the first mummy found frozen, rather than dried, and as a result her DNA is very well preserved. Mitochondrial DNA analysis demonstrated that the mummy shares ancestry with Native Americans and with the Ngobe people of Panama.

In 1990, Nevado Sabancaya, a volcano in the Peruvian Andes, began erupting. The heat of its eruption, as well as the hot ash that spewed from it cleared a layer of snow pack from the mountains in the area, including Mount Ampato. Five years later, in September 1995, anthropologist Johan Reinhard and his climbing partner Miguel Zarate climbed Mount Ampato to get a look at the active volcano nearby.

As they neared the summit, they spotted some bright feathers in the snow. Reinhard recognized the feathers as part of an Inca headdress of a ceremonial statue. It was made from a spondylous shell, the shell of an oyster that was sacred to the Incas, and it was preserved perfectly, with its textile clothing in excellent condition. The find had likely been uncovered by the melting of snow during the volcanic eruptions. Nearby, the two explorers noticed stones that appeared to be from an Inca ceremonial platform. As they looked down a ravine near the platform, they spotted a cloth bundle, which was frozen in place.

When Zarate hiked down the ravine to recover the bundle, he found a frozen mummy. The mummy was in the fetal position wrapped in colorful textiles made of alpaca (llama) wool. Pottery shards, bones from llamas and corn kernels surrounded her. The mummy was from a teenage girl, probably between 12 and 14 years old. Reinhard believed that Inca priests had sacrificed her, probably as part of a ritual to the gods they believed were part of the mountain. Reinhard recognized that mummy was a major archaeological find because she was the first frozen female mummy discovered in the Andes. She was later determined to be about 500 years old.

Reinhard and Zarate documented the site with photographs and collected the artifacts associated with the mummy. They knew that either exposure to sun and ash would damage the mummy or looters would destroy her remains and therefore they decided to take her from the mountain so she could be preserved. They carried the body down from the mountain and brought her to Universidad Catolica de Santa Maria in Arequipa, where refrigeration was arranged.

In 1996, the mummy was brought to the United States and several types of forensic techniques were performed to learn more about the girl's life, her last hours and about the people who may have descended from the Incas. Because a traditional autopsy would destroy the mummy, less invasive techniques were used. At Johns Hopkins Hospital in Baltimore, Maryland, computerized tomography (CT)—which is similar to a 3-dimensional x ray—was performed in order to determine the girl's bone structure and condition. Researchers at Johns Hopkins also removed small samples from the girl's heart and stomach using thin needles.

Radiologists determined that the mummy's bones were in good condition. She also had plenty of muscle mass and healthy teeth. She showed no evidence of disease or nutritional deficiency. This indicates that the girl was in excellent health at the time of her death. The girl's skull shows evidence of a violent blow. There was a fracture above the right eye and damage to the eye socket. The girl's brain was displaced to one side. These findings suggest that the girl was killed by being hit on the side of the head with a club, fracturing her skull. Subsequent bleeding filled the skull and pushed the brain to one side.

A sample of the contents of the girl's stomach contained only vegetable material. No meat was present. Because it probably took the girl several weeks to freeze, the fact that any material was found in her stomach suggests she had a full stomach when she died.

The tissue samples were sent to the Institute for Genomic Research in Rockville, Maryland. The mitochondrial DNA in the sample was copied using PCR (polymerase chain reaction) . In old tissues or tissues that might be degraded, mitochondrial DNA is often easier to study than nuclear DNA because cells contain many more copies of mitochondrial DNA than nuclear DNA. The mitochondrial DNA extracted from the Ice Maiden was of excellent quality, probably because she had been frozen rather than "dried" as is common in most mummies .

Mitochondrial DNA can be divided into two major regions. The first is a region that codes for the genes that make the molecular products used by mitochondria, which are sub-cellular organelles. The other region is a non-coding region and it does not contain any genes. Within the non-coding region, two regions on mitochondrial DNA have very high rates of mutation and are therefore optimal for studying differences among people. The two regions are called HV1 and HV2 (hypervariable region 1 and hypervariable region 2).

Comparisons of the sequence of the Ice Maiden's mitochondrial DNA from HV1 showed four differences from a reference sequence. Searching through databases of sequences of HV1, researchers found that these four differences exactly matched those differences found in a group of Native Americans. These people belong to a group called Haplotype A and they are one of the four founding lineages of Native Americans.

The HV2 sequence of mitochondrial DNA from the Ice Maiden varied in eight nucleotides from a reference sequence. These variations did not match any sequences found in databases of HV2 sequences. The closest match agreed in six of the eight nucleotide positions and was from a group of people called the Ngobe who live in Panama. Because of its unusual sequence, the Ice Maiden's mitochondrial DNA from the HV2 region is of great value for learning more about ancient people.

see also Mitochondrial DNA typing.