Decomposition Factors: Unraveling the Science of Human Decay

• Human Regulation and Reproduction
• Further Education (Key Stage 5)

Decomposition Factors: Unraveling the Science of Human Decay

Learning Objective

At the end of the lesson you will be able to identify and explain the factors affecting human decomposition.
Add learning outcomes!!! Describe, explain, evaluate, etc. 

What can you remember about human decomposition?

Understanding Decomposition

Definition:

Decomposition: The process by which organic substances are broken down into simpler forms.

Importance in Forensics:

Forensic Significance: Understanding decomposition aids forensic investigators in determining the time and circumstances of death.

Impact of Burial Conditions

Shallow Graves:

Factors: Limited protection from environmental elements, easier access for scavengers.

Effects: Faster decomposition, increased disturbance.

Deep Graves:

Factors: Greater protection, reduced access for scavengers.

Effects: Slower decomposition, better preservation.

Environmental Effects

Temperature:

Higher Temperatures: Accelerate decomposition.

Lower Temperatures: Slow down the process.

Terrain Conditions:

Waterlogged Areas: Slows decomposition, preserves bodies.

Dry Conditions: Accelerates decomposition.

Soil Types:

Acidic Soils: Accelerate decomposition.

Alkaline Soils: Slow down decomposition, promote preservation.

Decomposition Alternatives

Scavengers:

Presence: Accelerates decomposition, may scatter remains.

Absence: Slows down the process.

Insect Activity:

Role of Insects: Break down tissues, aid in decomposition.

Forensic Significance: Insect succession used to estimate 

time of death.

Decomposition Alternatives

Adipocere Formation:

Definition: Formation of a waxy substance from fat.

Forensic Significance: Slows decomposition, preserves body structure.

Mummification Stages:

Conditions: Dry environments.

Forensic Importance: Retains body and facial features.

Effect of Corpse Condition

Exposed and Unexposed Locations:

External Locations: Faster decomposition due to environmental exposure.

Internal Locations: Slower decomposition, influenced by indoor conditions.

Wrapped/Clothed Corpse:

Effects: May slow down decomposition, affect insect activity.

Forensic Consideration: Preservation of clothing as evidence. 

Effect of Corpse Condition

Trauma Influence:

External Trauma: May accelerate decomposition.

Internal Trauma: Influences internal decomposition rate.

Forensic Importance:

Link to Cause of Death: Understanding trauma effects aids 

in determining cause of death.

Corpse Location

The location of the corpse, such as woodlands, fields, houses, or vehicles, can affect decomposition processes.

What are some environmental factors affecting decomposition?

1. terrain
2. temperature
3. soil types
4. scavengers

How do burial conditions impact decomposition?

1. Grave decoration
2. Shallow and deep graves affect decomposition
3. Grave orientation - They must all face North
4. Grave size. The smaller the better

Which of the following is an alternative to skeletalization?

1. Petrification
2. Calcification
3. Fossilization
4. Adipocere

How does body condition affect decomposition?

1. Body colour. The paler, the quicker you decompose
2. Body odour. If you do not wash it affects decomposition
3. Body weight will affect decomposition
4. Exposed and unexposed locations affect decomposition

What can affect insect activity during decomposition?

1. sound levels. The vibrations attract insects
2. star visibility
3. air pressure
4. temperature and terrain affect insect activity

Write down 3 things you learned in this lesson.

Have students enter three things they learned in this lesson. With this they can indicate their own learning efficiency of this lesson.

Write down 2 things you want to know more about.

Here, students enter two things they would like to know more about. This not only increases involvement, but also gives them more ownership.

Ask 1 question about something you haven't quite understood yet.

The students indicate here (in question form) with which part of the material they still have difficulty. For the teacher, this not only provides insight into the extent to which the students understand/master the material, but also a good starting point for the next lesson.