Mummies Unwrapped

Science World, Oct 4, 1999 by Maia Weinstock

Scientists are searching for new clues to past lives, diets, and diseases. Where do they turn? Mummies, of corpse!

On a frigid, windy afternoon in March 1999, Johan Reinhard, a renowned arch archaeologist (expert on prehistoric cultures), stands atop the summit of 6,700-meters-(22,100-feet) high Mount Llullaillaco (yul-ya-Ya-ko) in northern Argentina, tie watch, crew gingerly lowers team member Jaen upside down by his ankles into a 1.8-meter (6-ft) deep, lark pit. Minutes later, they hoist Jaen but. He cradles a precious find in his arms--a mummy, or human corpse that survives for hundreds, even thousands of without decaying, or breaking down. The find is the frozen body of an Incan girl and buried 500 years ago!

Legend has it that children from noble were sacrificed in the hope Inca gods would how mercy during times of drought or famine. Reinhard and his crew unearth a total of three frozen bodies--two girls and a boy who died between the ages of 8 and 15 years old.

Archaeologists are piecing together mummies' past lives as never before. Thanks to new techniques like DNA analysis (analyzing genetic material) and an x-ray procedure called CT scanning, scientists can determine a mummy's diseases, last meal, and even cause of death.

Finding out what killed mummies years ago could even save lives today. "There's a lot of information you can derive from a mummy you just can't get from a skeleton," says David Hunt, an anthropologist at the Smithsonian Institution in Washington, D.C.

Scientists who study mummies now have evidence of diseases once thought to be nonexistent in ancient civilizations. Chagas' disease, for example, is a deadly ailment caused by the spread of parasites, organisms that live off other organisms. Chagas' now kills 43,000 people each year in the Americas. Researchers think studying mummies who had Chagas' before they died could offer clues to the disease's origins--and lead scientists to a cure.

Reinhard's newest discoveries count among the best-preserved mummies ever found. But ice children are merely one type of mummy. Mummies come in surprising shapes and forms, each with its own fascinating story to reveal how humans lived and died hundreds and thousands of years ago.

Cool Characters

The three children found in Argentina are ice mummies, bodies preserved in extreme cold. In the last century, ice mummies have been discovered in frigid sites the world over. The 500-year-old Greenland mummies--a family of six women, a young boy, and a baby--were found in Qilakitsoq (kill-a-KEET-sawk), Greenland, in 1972. In 1984, mummies of three English sailors were discovered in the Canadian Arctic after their boat was lost 150 years earlier!

Freezing conditions almost totally halt the decay of a corpse's body tissues. Most bacteria and fungi that normally rot dead bodies can't survive in subfreezing climates. Ice mummies like Reinhard's Incan children were buried in snow on purpose, but many ice mummies are preserved accidentally. In 1991, two hikers in the Italian Alps discovered a frozen 5,000-year-old mummy. Experts now think the mummy--nicknamed Ice Man--froze after a storm struck the mountain as he climbed it.

Since ice mummies found at Mt. Llulliallaco were so well-preserved, scientists examined their cells to uncover clues to their health during life. "If you study the tissue, you may find evidence that they had an illness," Hunt says. Scientists will be able to detect whether the ice mummies harbored any diseases--like Chagas'--that linger in humans today.

Scientists can also use genetic information from the ice mummies to determine their ancestry. They compare mummies' blood samples and DNA, or genetic code, with blood and DNA of modern people.

The Incan ice mummies should yield a wealth of information about pre-Columbian culture. "These mummies are very exciting--they're a glimpse into the past," says Hunt.

Bog Bodies

In the murky swamplands of northern Europe, almost 2,000 bog mummies have been scooped up by archaeologists and other travelers trekking through watery bogs. Bog mummies get their name from the peat bogs, or mossy marshes, in which they're buried. Bogs are composed of peat, a combustible, or burnable, substance used as fuel. Peat is made from moss, roots, and other organic matter.

Bog mummies are especially well-preserved. That's because the mossy peat in bog swamps shuts out oxygen, so bacteria and fungi--which survive on oxygen--can't get to bodies. "The bog isn't exactly like quicksand, but it can trap a person," says James Deem, author of Bodies From the Bog (Houghton Mifflin, 1998).

Bogs also contain acids called tannins, the same chemicals used to turn animal hides into leather. Tannins tend to make mummies' skin leathery and very dark brown (see picture). "Bog people are essentially tanned hides," says Hunt. Often bog mummies' leathery skin yields detailed fingerprints!

Tannins also speed up bone decay. So, though bog mummies' skin may survive intact for thousands of years, their bones almost always warp. No wonder bog mummies look flattened out!