The problem with the world’s oldest mummies

Meaning:Meticulous means extremely careful about small details — doing something slowly and thoroughly so that nothing gets missed. Here it tells you the Chinchorro did not just bury people quickly. Their mummification took months of exact, fiddly work: taking the body apart, drying it, rebuilding it with sticks, clay and a painted mask.

Meaning:Something makeshift is put together quickly out of whatever is on hand, as a rough stand-in for the proper version. It usually is not meant to last, though it often ends up lasting anyway. The fishing families' homes are makeshift because they were built fast from scrap materials, without permission or plans — which is part of why the site's protectors want them gone.

Meaning:To do something deliberately is to do it on purpose, after thinking about it first — the opposite of by accident. (The same word can also describe moving slowly and carefully, which comes from that same idea of thinking before you act.) That one word is what makes these bodies famous: plenty of ancient corpses survived by luck, but the Chinchorro chose to preserve theirs, thousands of years before the Egyptians did.

Here is the strange part of this story: bodies from 7,000 years ago are still lying in the ground with skin on them. Almost anywhere else on Earth they would have vanished long ago. Why?

When something dies, it does not disappear on its own. Bacteria and fungi — tiny living things already in the soil and inside the body — feed on the soft tissue and break it into simpler stuff. Biologists call this decomposition. The key fact is that those microbes are alive, and like every living thing they need water to grow. Take the water away and they simply cannot get going. The flesh dries out and hardens instead of breaking down.

You have eaten the proof. A fresh grape left in a cupboard goes soft, then fuzzy, then gross, in about a week — microbes are feeding on it. A raisin is the same grape with the water dried out of it, and it sits in that cupboard for a year without changing. Nothing was added to the raisin. Something was removed.

The Atacama is one of the driest deserts on the planet. Parts of it can go years without measurable rain. So a body buried there turns into the raisin, not the grape — and the Chinchorro's careful work got a 7,000-year head start from the weather.

Wherever water is missing — a desert, a freezer, a jar of salt, a bag of dried mango — decay slows down or stops. That is the whole trick behind mummies, jerky and the food in your pantry.

Getting on this list was supposed to solve the mummy problem. Instead it started a fight. To see why, you need to know what the list actually is — and what it is not.

UNESCO is a branch of the United Nations, the organisation that most of the world's countries belong to. It keeps a list of World Heritage sites: places judged so valuable to all of humanity that losing them would be everybody's loss. The Pyramids of Giza are on it. So are the Great Barrier Reef, the Taj Mahal and Yellowstone.

Now the part people usually get wrong. Being listed does not hand the place over to UNESCO. UNESCO owns nothing, and it has no police. Chile still owns the Chinchorro sites and still makes the rules there. What the country gets is expert help, access to money, and a lot of attention. What it gives back is a promise to look after the place. That is the deal: a promise, plus publicity.

Publicity cuts both ways, and Peru's Machu Picchu shows how. It joined the list in 1983, and being listed made it world-famous. Visitors poured in — so many that their footsteps started wearing down the stone paths of the very ruins they came to see. Peru's answer was to cap how many tickets it sells each day. The listing brought the money and the crowds that had to be limited.

That is exactly the squeeze in northern Chile. The listing opened the door to tourists who could pay to protect the mummies, and at the same time told a fishing village already living there that it should leave. So when you next read that somewhere was "named a World Heritage site", read it as a spotlight switching on — not as a fence going up.