When a dead body is buried in the soil, it goes through a process called decomposition. Decomposition is when the body breaks down into its smaller parts. This can happen through different processes like bacteria or fungi breaking down the tissues, or through insects and animals eating the body. The time it takes for a body to decompose depends on many factors like temperature, humidity, how deep the body is buried, and what kind of soil it is buried in.
Bodies that are buried in coffins usually take longer to decompose than those that are not because the coffin protects the body from being eaten by insects and animals and from being broken down by bacteria and fungi. The coffin also slows down air flow which also helps to slow down decomposition.
Embalming a dead body can also help to slow down decomposition. Embalming is when chemicals are used to preserve the body. This prevents bacteria from growing and keeps the tissues from breaking down as quickly.
Once a dead body starts to decompose, there are four main stages that it will go through: autolysis, putrefaction, black putrefaction, and skeletonization/mummification.
Autolysis happens when the cells of the body start to break down because they don’t have any oxygen. Putrefaction happens when bacteria start to grow in thebody and release gasses like methane and carbon dioxide which make thebody swell up and smell bad. Black putrefaction happens whenthe tissue turns black because of all ofthe bacteria that has grown in it. Skeletonization/mummificationhappens when all ofthe soft tissues have decomposedand only bones remain