Patrick is Associate Professor of Forensic Science at Northumbria University, UK. His broad interests concern the application of multi‐disciplinary forensic taphonomy into both current medico‐legal practice and the Evolutionary Anthropology of the deep past. He has a background in palaeoanthropology and archaeology, and spent much of his early academic life working on the biological and cultural evolution of the genus Homo during the Middle Pleistocene, a critical period that precedes the evolution of our own species and the advent of modern behaviours. In recent years he has been working in the field of forensic anthropology and human identification. He has extensive casework experience in both forensic anthropology and archaeology in the UK and sub‐Saharan Africa, including archaeology of fatal fires.
The session was started with a short introduction to the vast experience of Patrick. Then Patrick sir opened his imminent talk with an short and crisp introduction about what forensic Taphonomy is the the session was moved ahead with more amazing facts about the science of Taphonomy. So let's see some of those facts which I have detailed here.
Most people are very curious to know that what happens with the internal body parts when the person is dead. To find this, forensic taphonomy plays a significant role in investigating the facts of the dead body. First, we need to understand what is taphonomy? So, taphonomy is a binomial word that splits into two words- ‘taphos’ and ‘namos.’ It is the study of how bones transfers from living organisms to skeletonization and skeletonization to preserving stage. The aim of the forensic taphonomy is to construct the laws of burial. It helps in getting information about loss of bones, how things do preserve, how body reacts in different environment and many more. There are also subcategories of forensic taphonomy:
- Classical taphonomy - This involves spatial patterning and part representation to develop a logical narrative.
- Neo taphonomy – It uses experimental actualism to produce analogues. This also allows for falsifiability of taphonomic patterns which has been preserved.
Forensic taphonomy is used to interpret some of the actual findings like time since death, human intervention and search strategies. Forensic taphonomy differs from most other areas of taphonomy because of lack of time averaging, individual body as the unit of analysis, and also because of ground-truthed witness corroboration.
In today’s world, science has largely come out of something new taphonomic research facilities i.e. body farms. The ‘body farm’ term was first coined by Patricia Cornwell. The research by him was started with a human body at a small area, and it has developed into a 3-acre complex that contains remains of around 40 individuals at any one time. The aim of this research was to understand the natural process of decomposition of the body and scientific study of what happens after the death of a person.
At the initial stage, researchers have used unclaimed bodies from medical examiner’s offices but later on, people started donating their bodies on their own to the facility to help with forensic studies. Now, multiple taphonomic research facilities are there in the US, Europe, and Australia. Sydney taphonomy research facility provides arid region-specific data and the Tennessee taphonomy research facility pursues a broad range of studies into decomposition under all conditions. These conditions could be buried, unburied, underwater, or in structures.
Some of the different areas in which Forensic Taphonomy takes place like forensic entomology, archaeology, post-mortem interval, forensic pathology and many more
After getting to know all these research facility ideas, people might be wondering why human taphonomy research exists. The taphonomy research helps in understanding human decomposition to allow accurate and precise models of post-mortem interval. The taphonomy research facility also provides an understanding of how fast a body becomes skeletonized. The scientific study of bones and dead remains often leads to an analysis of volcanic organic compounds also.
The principal stages of decomposition of a body involve stages that take place after one another. These stages include; Fresh, Active decay, Advanced decay, and Dry or skeletonized.
Decay Process of a dead body
When the body goes through different physical manifestations after death then the first few changes that occur includes:
- Skin slippage happens because of hydrated enzymes.
- Skin peeling,
- Loosening of epidermis.
As the decomposition continues further, the process of marbling starts which include–
- Autolysis of red blood cells in large vessels occurs, as oxygen dissociates from hemoglobin and skin turn blue-purple color. This can be seen staining the blood vessels close to the skin.
- Bloating occurs because of large amount of decomposed gases inside the body due to the insects. The decomposition of gut contents and lungs can occur which result in purge fluid being expelled from orifices due to gas pressure.
- Discoloration of the body occurs which is caused by sulfur-based compounds bases, VOCs produced by intestinal bacteria reacting with hemoglobin and myoglobin creating sulpharmoglobin and sulphmyglobin-green in appearance.
A complex mix of VOCs is produced during the decomposition from the breakdown of carbohydrates and proteins and lipids. Putrescine and cadaverine are two signature odors created by the breakdown of proteins that can be detected by cadaver dogs.
The dried decomposition that takes place is mainly because of insects where forensic entomology comes in a major role. Blowflies get attracted towards dead body very quickly like within minutes and larval stages of insect results in rapid and significant tissue loss.
Life cycle of blowflies from egg to adult
The life cycle of blowflies depends on temperature and time (in hours) also to hatch completely. The time required for completion of development may be expressed as ‘accumulated degree hours (ADH) and accumulated degree days (ADD). The study of temperature and time gives the idea for studying PMI of a dead body.
Forensic taphonomy plays a significant role in court proceedings. It improves the search location and recovery skills of the evidence. Taphonomy research helps in building post-mortem narrative and long scale time since death estimation as well. The session was so interesting and thought-provoking. Every passing minute of this session was worth listening. So I would strongly suggest to visit the website foreniscevents.com or you may also go for the detailed session recording in our youtube channel forensic365