Let’s leave the mysteries of the spiritual after-life aside for our various religions to fight over, and concentrate on what really happens after death. It many not please many aesthetes, but the cyclic process is beautiful nonetheless.

From Raw Story:

“It might take a little bit of force to break this up,” says mortician Holly Williams, lifting John’s arm and gently bending it at the fingers, elbow and wrist. “Usually, the fresher a body is, the easier it is for me to work on.”

Williams speaks softly and has a happy-go-lucky demeanour that belies the nature of her work. Raised and now employed at a family-run funeral home in north Texas, she has seen and handled dead bodies on an almost daily basis since childhood. Now 28 years old, she estimates that she has worked on something like 1,000 bodies.

Her work involves collecting recently deceased bodies from the Dallas–Fort Worth area and preparing them for their funeral.

“Most of the people we pick up die in nursing homes,” says Williams, “but sometimes we get people who died of gunshot wounds or in a car wreck. We might get a call to pick up someone who died alone and wasn’t found for days or weeks, and they’ll already be decomposing, which makes my work much harder.”

John had been dead about four hours before his body was brought into the funeral home. He had been relatively healthy for most of his life. He had worked his whole life on the Texas oil fields, a job that kept him physically active and in pretty good shape. He had stopped smoking decades earlier and drank alcohol moderately. Then, one cold January morning, he suffered a massive heart attack at home (apparently triggered by other, unknown, complications), fell to the floor, and died almost immediately. He was just 57 years old.

Now, John lay on Williams’ metal table, his body wrapped in a white linen sheet, cold and stiff to the touch, his skin purplish-grey – telltale signs that the early stages of decomposition were well under way.

Self-digestion

Far from being ‘dead’, a rotting corpse is teeming with life. A growing number of scientists view a rotting corpse as the cornerstone of a vast and complex ecosystem, which emerges soon after death and flourishes and evolves as decomposition proceeds.

Decomposition begins several minutes after death with a process called autolysis, or self-digestion. Soon after the heart stops beating, cells become deprived of oxygen, and their acidity increases as the toxic by-products of chemical reactions begin to accumulate inside them. Enzymes start to digest cell membranes and then leak out as the cells break down. This usually begins in the liver, which is rich in enzymes, and in the brain, which has a high water content. Eventually, though, all other tissues and organs begin to break down in this way. Damaged blood cells begin to spill out of broken vessels and, aided by gravity, settle in the capillaries and small veins, discolouring the skin.

Body temperature also begins to drop, until it has acclimatised to its surroundings. Then, rigor mortis – “the stiffness of death” – sets in, starting in the eyelids, jaw and neck muscles, before working its way into the trunk and then the limbs. In life, muscle cells contract and relax due to the actions of two filamentous proteins (actin and myosin), which slide along each other. After death, the cells are depleted of their energy source and the protein filaments become locked in place. This causes the muscles to become rigid and locks the joints.

During these early stages, the cadaveric ecosystem consists mostly of the bacteria that live in and on the living human body. Our bodies host huge numbers of bacteria; every one of the body’s surfaces and corners provides a habitat for a specialised microbial community. By far the largest of these communities resides in the gut, which is home to trillions of bacteria of hundreds or perhaps thousands of different species.

The gut microbiome is one of the hottest research topics in biology; it’s been linked to roles in human health and a plethora of conditions and diseases, from autism and depression to irritable bowel syndrome and obesity. But we still know little about these microbial passengers. We know even less about what happens to them when we die.

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Putrefaction

Scattered among the pine trees in Huntsville, Texas, lie around half a dozen human cadavers in various stages of decay. The two most recently placed bodies are spread-eagled near the centre of the small enclosure with much of their loose, grey-blue mottled skin still intact, their ribcages and pelvic bones visible between slowly putrefying flesh. A few metres away lies another, fully skeletonised, with its black, hardened skin clinging to the bones, as if it were wearing a shiny latex suit and skullcap. Further still, beyond other skeletal remains scattered by vultures, lies a third body within a wood and wire cage. It is nearing the end of the death cycle, partly mummified. Several large, brown mushrooms grow from where an abdomen once was.

For most of us the sight of a rotting corpse is at best unsettling and at worst repulsive and frightening, the stuff of nightmares. But this is everyday for the folks at the Southeast Texas Applied Forensic Science Facility. Opened in 2009, the facility is located within a 247-acre area of National Forest owned by Sam Houston State University (SHSU). Within it, a nine-acre plot of densely wooded land has been sealed off from the wider area and further subdivided, by 10-foot-high green wire fences topped with barbed wire.

In late 2011, SHSU researchers Sibyl Bucheli and Aaron Lynne and their colleagues placed two fresh cadavers here, and left them to decay under natural conditions.

Once self-digestion is under way and bacteria have started to escape from the gastrointestinal tract, putrefaction begins. This is molecular death – the breakdown of soft tissues even further, into gases, liquids and salts. It is already under way at the earlier stages of decomposition but really gets going when anaerobic bacteria get in on the act.

Putrefaction is associated with a marked shift from aerobic bacterial species, which require oxygen to grow, to anaerobic ones, which do not. These then feed on the body’s tissues, fermenting the sugars in them to produce gaseous by-products such as methane, hydrogen sulphide and ammonia, which accumulate within the body, inflating (or ‘bloating’) the abdomen and sometimes other body parts.

This causes further discolouration of the body. As damaged blood cells continue to leak from disintegrating vessels, anaerobic bacteria convert haemoglobin molecules, which once carried oxygen around the body, into sulfhaemoglobin. The presence of this molecule in settled blood gives skin the marbled, greenish-black appearance characteristic of a body undergoing active decomposition.

Colonisation

When a decomposing body starts to purge, it becomes fully exposed to its surroundings. At this stage, the cadaveric ecosystem really comes into its own: a ‘hub’ for microbes, insects and scavengers.

Two species closely linked with decomposition are blowflies and flesh flies (and their larvae). Cadavers give off a foul, sickly-sweet odour, made up of a complex cocktail of volatile compounds that changes as decomposition progresses. Blowflies detect the smell using specialised receptors on their antennae, then land on the cadaver and lay their eggs in orifices and open wounds.

Each fly deposits around 250 eggs that hatch within 24 hours, giving rise to small first-stage maggots. These feed on the rotting flesh and then moult into larger maggots, which feed for several hours before moulting again. After feeding some more, these yet larger, and now fattened, maggots wriggle away from the body. They then pupate and transform into adult flies, and the cycle repeats until there’s nothing left for them to feed on.

Under the right conditions, an actively decaying body will have large numbers of stage-three maggots feeding on it. This ‘maggot mass’ generates a lot of heat, raising the inside temperature by more than 10°C. Like penguins huddling in the South Pole, individual maggots within the mass are constantly on the move. But whereas penguins huddle to keep warm, maggots in the mass move around to stay cool.

“It’s a double-edged sword,” Bucheli explains, surrounded by large toy insects and a collection of Monster High dolls in her SHSU office. “If you’re always at the edge, you might get eaten by a bird, and if you’re always in the centre, you might get cooked. So they’re constantly moving from the centre to the edges and back.”

Purging

“We’re looking at the purging fluid that comes out of decomposing bodies,” says Daniel Wescott, director of the Forensic Anthropology Center at Texas State University in San Marcos.

Wescott, an anthropologist specialising in skull structure, is using a micro-CT scanner to analyse the microscopic structure of the bones brought back from the body farm. He also collaborates with entomologists and microbiologists – including Javan, who has been busy analysing samples of cadaver soil collected from the San Marcos facility – as well as computer engineers and a pilot, who operate a drone that takes aerial photographs of the facility.

“I was reading an article about drones flying over crop fields, looking at which ones would be best to plant in,” he says. “They were looking at near-infrared, and organically rich soils were a darker colour than the others. I thought if they can do that, then maybe we can pick up these little circles.”

Those “little circles” are cadaver decomposition islands. A decomposing body significantly alters the chemistry of the soil beneath it, causing changes that may persist for years. Purging – the seeping of broken-down materials out of what’s left of the body – releases nutrients into the underlying soil, and maggot migration transfers much of the energy in a body to the wider environment. Eventually, the whole process creates a ‘cadaver decomposition island’, a highly concentrated area of organically rich soil. As well as releasing nutrients into the wider ecosystem, this attracts other organic materials, such as dead insects and faecal matter from larger animals.

According to one estimate, an average human body consists of 50–75 per cent water, and every kilogram of dry body mass eventually releases 32 g of nitrogen, 10 g of phosphorous, 4 g of potassium and 1 g of magnesium into the soil. Initially, it kills off some of the underlying and surrounding vegetation, possibly because of nitrogen toxicity or because of antibiotics found in the body, which are secreted by insect larvae as they feed on the flesh. Ultimately, though, decomposition is beneficial for the surrounding ecosystem.

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According to the laws of thermodynamics, energy cannot be created or destroyed, only converted from one form to another. In other words: things fall apart, converting their mass to energy while doing so. Decomposition is one final, morbid reminder that all matter in the universe must follow these fundamental laws. It breaks us down, equilibrating our bodily matter with its surroundings, and recycling it so that other living things can put it to use.

Ashes to ashes, dust to dust.

Read the entire article here.

Image: Still-Life with a Skull, 17th-century painting by Philippe de Champaigne. Public Domain.