4104FSBMOL - Lecture 3a - Decompostion 1: Stages, Characteristics and intro to PMI estimation.

Question 2

DEFINITION of Decomposition.

Answer 2

Either the decaying caused by bacteria or fungal action; reduction of the body of a living organism to simpler forms of matter; a continual process that can take weeks to years, depending on the environment; a process that contributes to the cycling of energy and nutrients in the environment or a process that is necessary for all life on earth.

Question 3

DEFINITION of Taphonomy.

Answer 3

It comes from Taphos Nomos which means burial of law; it is the study of the processes that affect the decomposition, dispersal, erosion, burial, and re-exposure of organisms after, at, and even before death.

Question 4

What are the 5 Stages of Decomposition?

Answer 4

1. Fresh.
2. Bloat.
3. Active Decay.
4. Advanced Decay.
5. Skeletonization.

Question 5

What happens in the Fresh Stage of Decomposition?

Answer 5

• Up to 72 hours long.
• Typified by alga mortis, liver mortis, rigor mortis, and the immediate changes to the body.

Question 6

What happens in the Bloat Stage of Decomposition?

Answer 6

• Distension of the abdominal cavity due to the build up of gases.

Question 7

What happens in the Acive Decay Stage of Decomposition?

Answer 7

• Insect activity occurs.
• ‘At its height’.
• Active movement of Maggot Mass.

Question 8

What happens in the Advanced Decay Stage of Decomposition?

Answer 8

• Insect activity dwindled.
• Beetles.
• Drying out of tissues.
• Mummification.

Question 9

What happens in the Skeletonization Stage of Decomposition?

Answer 9

• All tissues removed/ fully dreid out.
• Extreme environments such as the cold don’t allow the body to get to this stage - it preserves the body.