WEBVTT - Why Are Peat Bogs So Good at Preserving Human Remains? 0:00:02.040 --> 0:00:07.040 Welcome to brain Stuff from how Stuff Works, Hey, brain Stuff, 0:00:07.120 --> 0:00:10.520 Lauren voke obam here. Bogs are pretty awesome as far 0:00:10.600 --> 0:00:14.000 as sweeping mud fields of dead buried plants go. They 0:00:14.080 --> 0:00:16.560 store the energy of generations of plants in their mass, 0:00:16.600 --> 0:00:20.640 which can be harvested as pete. They're also havens for mummies. 0:00:21.239 --> 0:00:24.680 Artifacts buried beneath bogs, including human bodies, may be kept 0:00:24.720 --> 0:00:28.000 in astonishingly good condition for thousands and thousands of years. 0:00:28.520 --> 0:00:31.320 They've all got stories to tell, and today we'll look 0:00:31.320 --> 0:00:35.720 at the weird science that makes their preservation possible. Common 0:00:35.800 --> 0:00:38.520 in cool, wet parts of the world, bogs are water 0:00:38.600 --> 0:00:42.240 logged grounds that form when decaying plant matter, known as pete, 0:00:42.400 --> 0:00:46.320 accumulates in low lying areas. Bogs are usually found in 0:00:46.360 --> 0:00:49.440 cool climates and often in lake basins created by ice 0:00:49.520 --> 0:00:51.960 age glaciers that no longer get a steady flow of 0:00:52.080 --> 0:00:55.560 river or stream water over time. Mosses cover the heap 0:00:55.600 --> 0:00:58.680 like a blanket, and in most cases, this mossy layer 0:00:58.800 --> 0:01:02.760 is primarily made of am called sphagnum. Sphactum. Moss has 0:01:02.760 --> 0:01:06.479 the power to transform an entire landscape. Water or dirt 0:01:06.480 --> 0:01:08.440 trapped beneath sheets of it. Will be cut off from 0:01:08.480 --> 0:01:11.920 the normal supply of oxygen from the atmosphere. Also, sphagnum 0:01:12.000 --> 0:01:15.720 soaks up calcium and magnesium, which makes the underlying soil 0:01:15.800 --> 0:01:20.119 and water mildly acidic. Since bacteria and fungi find those 0:01:20.160 --> 0:01:24.880 conditions inhospitable, the dead vegetation decomposes at a phenomenally slow rate. 0:01:25.400 --> 0:01:28.800 Instead of breaking down right away, it lingers piling up. 0:01:28.840 --> 0:01:32.399 Over time, masses of the botanical waste gradually turn into pete, 0:01:32.680 --> 0:01:36.360 a soggy, mud colored substance. Pete can be used as 0:01:36.400 --> 0:01:39.000 animal bedding and as a fossil fuel, which makes it 0:01:39.040 --> 0:01:41.920 an important commodity in places like the Irish Midlands and 0:01:42.000 --> 0:01:44.720 in Scotland, where it's the traditional fuel for fires that 0:01:44.800 --> 0:01:47.760 dry out grain to make Scotch whiskey, imparting smoke and 0:01:47.800 --> 0:01:51.520 its flavors along with that heat. But two archaeologists, pete 0:01:51.600 --> 0:01:53.880 is a lot less valuable than the human corpses that 0:01:53.960 --> 0:01:57.760 sometimes come with it. Bogs have long fascinated humans, not 0:01:57.880 --> 0:02:00.840 just for their fossil fuels. The spongee oil has intrigued 0:02:00.840 --> 0:02:03.680 people as far back as the Bronze Age. Many people 0:02:03.720 --> 0:02:06.880 died in these bogs or were placed there after their deaths, 0:02:06.920 --> 0:02:09.560 and these bog bodies, as they're known, have been found 0:02:09.600 --> 0:02:13.600 all over the world. The wetlands of northwestern Europe, for instance, 0:02:13.680 --> 0:02:16.880 is a bog body hub. Hundreds of these corpses have 0:02:16.960 --> 0:02:20.280 turned up in Germany, England, the Netherlands and neighboring countries. 0:02:20.720 --> 0:02:24.320 In eleven pete harvesters working in Ireland accidentally ran over 0:02:24.360 --> 0:02:27.280 a Bronze age corpse with a milling machine. Dubbed the 0:02:27.320 --> 0:02:30.120 Castle Man. The harvester found all that was left of 0:02:30.120 --> 0:02:33.320 an adult male who probably died in his twenties. His 0:02:33.400 --> 0:02:36.040 body was riddled with injuries, including a broken arm and 0:02:36.040 --> 0:02:38.920 a nasty cut across the backside. Some of these may 0:02:38.919 --> 0:02:41.000 have been caused by the compressing weight of the bog 0:02:41.040 --> 0:02:45.000 moss above him or the blades of that milling device. Nevertheless, 0:02:45.200 --> 0:02:47.799 archaeologists have reason to suspect that the casual Man was 0:02:47.840 --> 0:02:52.600 a ritualized sacrifice victim. Other European bog bodies have displayed 0:02:52.600 --> 0:02:56.280 stab wounds, slit throats, and evidence of torture. Historians think 0:02:56.360 --> 0:02:59.600 that the local wetlands were once a hotbed for religious sacrifices. 0:03:00.800 --> 0:03:03.359 Carbon dating tells us the casual man perished about four 0:03:03.400 --> 0:03:07.080 thousand years ago, seven centuries before King Tuton Common was born. 0:03:07.600 --> 0:03:10.480 To date, he's the oldest European bog body on record 0:03:10.560 --> 0:03:14.240 with intact skin. That's right, the corpse of somebody who's 0:03:14.280 --> 0:03:17.360 been dead for four millennia still has its skin attached, 0:03:17.840 --> 0:03:20.639 and this isn't a fluke. Lots of bog bodies retain 0:03:20.720 --> 0:03:23.639 some or all of their original skin. The Taaland Man, 0:03:23.760 --> 0:03:26.040 a twenty three hundred year old corpse recovered from a 0:03:26.040 --> 0:03:29.640 Denmark peat bog in nineteen fifty, has skeletonized hands, but 0:03:29.720 --> 0:03:32.919 elsewhere his skin is so well preserved that little details 0:03:32.919 --> 0:03:36.720 like the wrinkles on his forehead are still visible. Although 0:03:36.720 --> 0:03:40.000 the Taaland Man's skin didn't rot away, the mummification process 0:03:40.080 --> 0:03:43.520 did change its appearance and texture. Like the casual man 0:03:43.560 --> 0:03:46.560 and lots of other bog bodies, he sports leathery, dark 0:03:46.600 --> 0:03:49.720 brown skin. Some of them also have preserved hair that 0:03:49.840 --> 0:03:53.240 was dyed red after death. This is most likely caused 0:03:53.240 --> 0:03:56.800 by a recently discovered polymer called sphagnum, which seeps out 0:03:56.800 --> 0:03:59.800 of dead sphagnum moss. If you think of leather, it's 0:04:00.040 --> 0:04:02.960 through a process called tanning that strengthens the bonds between 0:04:03.000 --> 0:04:05.760 some of the natural fibers in animal hides. As a 0:04:05.800 --> 0:04:08.920 tanning agent, sphagnan has the same effect on human skin, 0:04:09.240 --> 0:04:14.320 rendering it tough and tea colored. Sphagnan also binds with nitrogen, 0:04:14.440 --> 0:04:17.880 which bacteria need to survive, so by removing nitrogen from 0:04:17.920 --> 0:04:21.200 the environment, sphagnan helps prevent the spread of microorganisms that 0:04:21.240 --> 0:04:26.280 would normally be breaking down human and animal remains. And Furthermore, sphagnan, 0:04:26.440 --> 0:04:29.320 along with the acid that it turns into, pulls calcium 0:04:29.400 --> 0:04:33.360 right out of dead bodies. Bones get weakened in the process. 0:04:33.360 --> 0:04:36.400 Although sphagnan does a fine job of preserving skin, it's 0:04:36.440 --> 0:04:40.200 calcium thievery isn't great for skeletons. Mummies have been found 0:04:40.240 --> 0:04:43.080 in certain bogs with soft, extra flimsy bones that are 0:04:43.120 --> 0:04:46.240 about astarte's cardboard and that have been distorted by heavy peat, 0:04:47.120 --> 0:04:51.440 but that's assuming the decalcification process doesn't altogether eliminate bones. 0:04:51.920 --> 0:04:54.640 Lots of bog bodies have been found missing bones, and 0:04:54.720 --> 0:04:57.600 some of the mummies are totally boneless. The latter are 0:04:57.640 --> 0:05:01.080 basically human shaped bags of leatheries in wrapped around some 0:05:01.120 --> 0:05:05.240 pickled organs. Not all bogs are so hostile to bones, though, 0:05:05.600 --> 0:05:08.599 the water's acidity level varies from bogged bog and this 0:05:08.720 --> 0:05:13.120 impacts corpse preservation. Archaeologists have discovered that in really acidic 0:05:13.120 --> 0:05:15.680 peat bogs, the resident mummies have lots of skin and 0:05:15.720 --> 0:05:19.360 soft tissue and weak or non existent bones, But there 0:05:19.400 --> 0:05:23.200 are some boggy places with relatively alkaline water. Here the 0:05:23.320 --> 0:05:26.760 environment pretty much has the opposite effect on corpses. A take, 0:05:26.880 --> 0:05:30.359 for example, the Windover Archaeological Site, a peat bottomed pond 0:05:30.400 --> 0:05:32.880 in Florida that became the final resting place for dozens 0:05:32.880 --> 0:05:35.520 of Native Americans between seven and eight thousand years ago. 0:05:36.240 --> 0:05:38.760 Skeletal remains from a hundred and sixty eight people have 0:05:38.839 --> 0:05:41.839 turned up in the peat. A large deposit of crushed 0:05:41.920 --> 0:05:44.640 up snail shells lying under the pond supplies the water 0:05:44.680 --> 0:05:48.680 with magnesium and calcium carbonates That makes the water more alkaline, 0:05:48.920 --> 0:05:53.440 neutralizing the spagnum to an extent. Instead of mummified skin bags, 0:05:53.560 --> 0:05:56.599 the bog is rife with naked bones and skeletons a 0:05:56.640 --> 0:05:59.119 bear as they are on the outside. The ancient bones 0:05:59.160 --> 0:06:01.960 had a big surprise sides in store for scientists. Brain 0:06:02.040 --> 0:06:04.480 tissue was found in more than ninety of the windover 0:06:04.560 --> 0:06:09.120 pond skulls, making them extra fascinating fines by the way, 0:06:09.279 --> 0:06:12.520 bonus fact of the episode. Most carnivorous plants, such as 0:06:12.560 --> 0:06:15.800 sundews and pitcher plants grow in bog soils, which tend 0:06:15.839 --> 0:06:19.120 to be nutrient poor. Eating animal prey is a strategy 0:06:19.160 --> 0:06:27.000 that helps them obtain vital nutrients. Today's episode was written 0:06:27.040 --> 0:06:29.599 by Mark Bancini and produced by Tyler clayg for iHeart 0:06:29.600 --> 0:06:31.839 Media and how Stuff Works. For more on this and 0:06:31.880 --> 0:06:34.440 lots of other topics that aren't too bogged down, visit 0:06:34.440 --> 0:06:47.880 our home planet to stuff works dot com.