Lecture 9 - Forensic Anthropology and Taphonomy

Question 1

stages of decomposition in order

Answer 1

fresh 
bloat 
active decay 
advanced decay 
skeletonised

Question 2

Fresh

Answer 2

From the moment of death to the onset of bloating (This is where rigor mortis > livor mortis > algor mortis happens)

Body produces gases, autolysis (body eats itself and produces gases, body is broken down by its enzymes) and putreification occurs

Question 3

Three things that happen in fresh stage of decomposition

Answer 3

Rigor mortis
livor mortis
then algor mortis

Question 4

rigor mortis

Answer 4

stiffening of the muscles

Question 5

livor mortis

Answer 5

colour change due to the gravitational pooling of blood

Question 6

algor mortis

Answer 6

temperature change

Question 7

Bloat stage

Answer 7

Epidermis slips off, hair will loosen and slip off with skin, abdominal discolouration

Distension of the abdomen

Discolouration/marbling, green like discolouration underneath the skin

Sometimes the skin slips off

Hair shrivels and shrinks back, tissues become detached from each other (hair and nails do not keep growing after death)

Question 8

Active decay stage

Answer 8

Active decay - Tissues and organs soften and degenerate then liquefy, foul odour, and body eventually collapses

Bursting of the abdominal cavity

Decomposing liquefaction occurring in abdomen from the gut bacteria explodes and surrounds other tissues, get smell of death in this phase (very stinky)

No structure to hold body together anymore so the body collapses

Body tissues liquify and purge out

Question 9

Advanced decay stage

Answer 9

Advanced decay - Remaining flesh desiccates and shrinks, surface tissue assumes leathery texture, and less pungent odour

Less smelly

Skin can start to dry up and mummify

Question 10

Skeletonised stage

Answer 10

Skeletonised - Dry body now decays very slowly, and may become completely skeletonised

All soft tissue has decomposed so only have bones and teeth

Skeletonisation is the stage that the forensic anthropologist deals with, in these situations they can also be dealing with mummified tissue and hair

Question 11

body goes through autolysis where

Answer 11

the body is broken down by its own enzymes i.e. the body is eating itself

Question 12

when you have animal activity going on around the remains then you

Answer 12

have much more accelerated rate of decomposition

Question 13

Primary level of human identification

Answer 13

1- fingerprints
2- dental
3- DNA

Question 14

Secondary level of human identification

Answer 14

Anthropology/disease/injury/scars/unique tattoos

If you have an unknown skeleton found then can use anthropology to look at diseases and injuries and to provide a basic biological profile of what the bones can tell us
If there was soft tissue remaining or mummified tissue present then may use scars or unique tattoos to help identify the person
Although anthropology is not up their as a primary method of identification it is still very useful as a secondary method to help narrow down the search to narrow down you might be searching dental records for or looking at the missing persons list for

Question 15

tertiary level of human identification

Answer 15

unique clothing, jewellery

Question 16

circumstantial level of human identification

Answer 16

documentation, face, generic tattoos, clothing, jewellery

Question 17

Forensic agencies involved in fresh stage

Answer 17

forensic pathologist, fingerprint expert, DNA analyst, odontology

Question 18

Forensic agencies involved in bloat stage

Answer 18

forensic pathologist, fingerprint expert, DNA analyst, odontology

Question 19

Forensic agencies involved in active decay stage

Answer 19

fingerprint expert, DNA analyst, odontology

Question 20

Forensic agencies involved in advanced decay stage

Answer 20

fingerprint expert, DNA analyst, odontology

Question 21

Forensic agencies involved in skeletonised stage

Answer 21

forensic anthropologist, odontologist, DNA?

Question 22

Skeletonisation …

Answer 22

Refers to the completion of soft tissue decomposition, where only the hard tissues of the skeleton remain
Skeleton includes the bones and the teeth (dentition)
In many forensic cases there is still mummified soft tissue present on the skeleton (it is never totally clean usually) and in some circumstances you need to remove it before examination

Question 23

The skeleton itself can also undergo postmortem changes =

Answer 23

taphonomy

Question 24

forensic anthropology and the skeleton

Answer 24

Our skeleton tells a story about the evolution of our species and of life (and death)…
Forensic anthropologist used in these examples of mass disasters
Look at skeleton
In a forensic context looking at the circumstances of death
Everything about you is etched in your bones such as your childhood, how healthy you were, how well you grew, did you have any illnesses when you were a kid, nutritional status, family of origin, where you drank your water from as a kid and was it different from when you were an adult etc etc
Your skeleton tells a story of your life, in a forensic setting your skeleton tells you a more of a story of death or the circumstances of your death
Need to do your best for the deceased and for the families

Question 25

The anthropological protocol

Answer 25

Is it bone? 
Human? 
Forensic context? 
How many individuals? 
Biological profile = sex, age at death, ancestry, stature
trauma and pathology 
identifying characteristics

Question 26

Human vs non-human (other animal)

Answer 26

Look at two main features = maturity and architecture

Question 27

human vs non-human - maturity

Answer 27

Forensic anthropologists need to know about the human skeleton and how it develops and how children’s skeletons developments

Growth and development
Unfused epiphyses and other structures
Example of the human pelvis and knowing maturity …. For adults their are two os coxae and one sacrum that make up the pelvis whereas a neonatal (brown bones on image) version is 3 bones rather than one bone and as you get older, your bones grow within themselves at their own growth plates and then when you reach the age of maturity which is different for individuals based on family, lifestyle, sex and other factors your bones will actually fuse together and the cartilaginous growth plates that are in between the two aspects of bone will disappear and then you stop growing so this is one way that we age and even though it is different for each individual it is still following a set pattern

Question 28

human vs non-human - architecture

Answer 28

Architecture - when we come to think of humans as a species is the shape of our bones and our architecture

Shape differences
Biped vs quadruped
Humans are habitually bipedal therefore our bones are a certain way and are identifiable by this, makes our bones very unique to us

Muscle rugosity

Question 29

Components of the biological profile

Answer 29

sex 
age
ancestry 
stature (height)
Trauma and pathology 
Identifying characteristics

Question 30

Sex differences in the pelvis

Answer 30

Female features 
Greater than 90 degrees angle at the subpubic angle *** 
Sacrum tilted back 
Flared ilia
Male features 
Less than 90 degrees angle at the subpubic angle *** 
Sacrum tilted forward 
Narrow ilia 

The pelvis is an evolutionary difference that is there no matter your ancestry

Question 31

What is the sex (not gender)?

Answer 31

Try look at pelvis before skull

All the differences in skulls between sexes due to muscle mass

Males have lerger muscle attachments, but not a fixed rule i.e. men can have more gracile skulls

Question 32

Age estimation in children ….

Answer 32

Children: Based on maturity and fusion of bones.
Look at the diaphysis (long bit) and epiphyses (ends of the bone) and they have ossification centres in the middle of them so this is where the cartilage starts to ossify and then get bigger and longer and then due to your genetics and your environment you will at some point stop growing
Have ossifications centres in the middle of the bones **

Question 33

age estimation in adults …

Answer 33

Adults: Based on degradation of surfaces.

Question 34

subadult age estimation …

Answer 34

~450 ossification centers at birth
450 tiny little bits of bones that eventually fuse and form into 206 adult bones
Eventually fuse to become 206 bones in adulthood
Track ossification center development and fusion for aging.
Tracking means you can help to determine age

Question 35

age estimation and the skull

Answer 35

Skull is a number of different bones when you are growing, also have cartilaginous structures in between the bone which will allow the expansion and growth of the skull and then eventually when you stop growing the bones will knit together at places called suture margins but even as a 25 to 27 year old you can still have one particular suture that is unfused which is right in the middlel

Question 36

subadult aging and dental

Answer 36

Dental eruption and development
Both forensic odontologists and forensic anthropologists should know eruption and development patterns of children

Relatively stable and accurate

Question 37

pubic symphysis

Answer 37

front of the pelvis
Has wad of cartilage in between it
Wears away over time, degrades overtime to a point where the bone starts wearing away, over time you have some changes which start off nice and billowy which then starts degrading and producing a smooth surface and then the cartilage is essentially gone and starts sweating away even more, these changes are quite well documented although they do not give you an exact age and instead give you an age range that the pelvic human remains could belong
Then as adults you have degenerative patterns
Cant give you a specific age but can give you an age range

Question 38

Ancestry (not ethnicity)

Answer 38

eye orbits change shape
Nose change shape in skull
Can see soft tissue changes between ancestry groups and these are affected in your bones as well
Polynesian remains - rocker jaw, jaw has a rounded corner will rock on a table (not always true), European jaw will not rock on the table, not always true because we have very diverse and mixed ancestry groups

Question 39

skeletal trauma analysis

Answer 39

Timing of trauma
(ante-, peri-, postmortem)

Force that caused trauma
(blunt, sharp, projectile, misc.)

Number of wounds

Sequence of wounds

Placement of wounds
Can start to rebuild the circumstances/story of what happened around the time of death

Question 40

Main concerns for a forensic anthropologist

Answer 40

The recovery and analysis of skeletonised humans for law enforcement agencies.

The identification of victims, perimortem trauma, and postmortem disturbance for presentation in court.
Want to identify the trauma so that it can be used in the legal proceedings

Antemortem pathology – victim identification; evidence of disease and trauma before death.

Perimortem trauma – evidence of trauma around the time of death “manner of death”

Postmortem trauma – disturbance after death

Taphonomy – plants, animals, insects, or other natural forces that explain position/condition of body

Question 41

Antemortem pathology

Answer 41

Antemortem pathology – victim identification; evidence of disease and trauma before death.

Question 42

Perimortem trauma

Answer 42

Perimortem trauma – evidence of trauma around the time of death “manner of death”

Question 43

Postmortem trauma

Answer 43

Postmortem trauma – disturbance after death

Question 44

Taphonomy and forensic anthropology

Answer 44

Taphonomy – plants, animals, insects, or other natural forces that explain position/condition of body

Question 45

Forensic anthropologists and crime scene search/recovery

Answer 45

Assist law enforcement in the search and recovery of human remains
Certain sequence of events in the decomposition of bodies so forensic anthropologists can help especially since they know hallmarks for the different stages that you can look out for
Death in water presents with the body in a very specific face down and limbs hanging down limply in the water
Can look at ground differences, usually a forensic archeologist doing this

Question 46

Surface scatter

Answer 46

missing persons are most likely to be found above ground decomposition with surface scatter, they are not buried and so their body/body parts are found on the surface and will be found disarticulating on the surface
Skull acts like a ball when it becomes detached from the jaw, rolls to any contour
The mandible and spine are not very movement orientate shapes so usually remain where the body was first positioned/where the person became deceased
Legs and arms may be taken away by scavengers so may be further away from the rest of the body
These are all clues that can be looked at to identify the circumstances around the death

Question 47

burial excavations - cold cases

Answer 47

Re-exhume someone or further evidence has come up or clandestine burial (unmarked grave) and you need to remove that body from that location are scenarios where forensic anthropologists can be involved in burial excavations
`

Question 48

What is forensic taphonomy?

Answer 48

“Forensic taphonomy is the study of the postmortem changes to human remains, focusing largely on environmental effects—including decomposition in soil and water and interaction with plants, insects, and ” other animals.

Question 49

Three factors of taphonomy

Answer 49

The grave (environmental factors) 
The soil type and pH, vegetation, near water or not etc can affect the bodies 

The assailant (behavioural factors)
Was it a quick dug grave? Was it preplanned? Was the grave deep?
Can discuss the behaviour of the assailant
If it is a homicidal investigation, can judge the character of the person from various cues

The remains (individual factors)
Differences of being human
e.g. all have different microbiomes which can affect decomposition

Question 50

taphonomic factors that will influence the remains when they are found

Answer 50

buried, concealed or burnt
- soil pH, texture and moisture

Method (i.e. wrappings/clothes, coffin, lime, mass burial)

Scavenging activity – trauma?
protecting body from scavengers by covering them slows down decomposition whereas exposed remains are more likely to have fastened decomposition due to scavengers having access to the remains

Climate (Incl. soil, water or air temp)

Microorganisms

Insect activity

Question 51

Above ground decomposition

Answer 51

Major factor that influences the body is the climate

Temperature is one of the most influential factors
When the body is above the ground and decomposition the biggest influence on the rate of decomposition is the climate/temperature
Warm temperatures increase rate of decomposition
the body will skeletonise faster
Associated with an increase in biological activity

Precipitation
if it is raining the flies are not going to be out

Humidity

Sun/shade
savengers may not want to be in the direct sunlight

Wind
All of these will affect the decomposition rate, also affects scavengers which again influences the decomposition rate

Question 52

Summer decomposition of pig

Answer 52

Two very different environments
Sydney one was in blue mountains and at a change on altitude and the humidity was so dry that it meant that the pig decomposition was affected, so the pig mummified the body since it all got dried out

decomposition is faster for both because of the summer climate and environmental features of that time of year

Question 53

winter decomposition of pig

Answer 53

takes longer for decomposition

Question 54

Forensic implications of climate

Answer 54

Insect activity will accelerate decomposition
Forensic entomology used to estimate time since death
Insect colonization and succession
Decomposition rate varies when insects are restricted

Question 55

forensic implications of scavengers

Answer 55

Scavengers will influence decomposition rates

Scavengers can affect estimation of time since death

Dispersal of skeletal elements may hinder locating decomposed remains
less of an affect in NZ
can affect evidence and leave their own evidence, called postmortem trauma and it looks different to trauma that occurred around the time of death

Question 56

Burial as a body disposal method

Answer 56

Less insects
as you go deeper down

Less scavengers

Deeper burial = slower decomposition

Shallower burials = ambient temperature
Also coffin/wrapping will stop any interaction with the surrounding burial environment and the body so you might get a lot of adipocere forming to protect the body

Question 57

Moisture and soil texture

Answer 57

Sandy Soils drain moisture

Clay soils retain moisture

Adipocere formation
body fat hydrolysis, act as a waxy fatty layer and protects skeleton and can even protect soft body tissues even the soft tissues

Question 58

adipocere formation

Answer 58

An exposed, insect-infested body or a body in a warm environment is unlikely to form deposits of adipocere.

Question 59

Wrappings and body disposal

Answer 59

Look the vegetation because plastic stops the nutrients seeping
Uncovered would provide increase in vegetations

Question 60

cloth wrapping

Answer 60

Inhibits decomposition

Prevents access to microorganisms

May promote adipocere formation
in this case, good wrapping can slow down and event halt decomposition i.e. can preserve the body so may even have fingerprints, facial recognition etc.

Question 61

lime

Answer 61

Restricts microbial activity
stopping microbial activity = stops decomposition

Highly alkaline pH

Slows decomposition and can cause preservation
can cause preservation of soft tissue

Question 62

Fire damage is

Answer 62

Forte of the forensic anthropologist because all the soft tissue has been removed
pugilistic posture

Question 63

pugilistic posture

Answer 63

flexion of all major muscle groups
Occurs when the body is fresh
If body already dead before fire, rigor mortis occurred then this posture does not occur ***
The main thing being investigated is whether the fire caused the death or whether the fire was used to cover up the death
Burn pattern to do with flexion, red bits get burned first, blue bits on the image are protected due to the position