Transcript Paleoanthropology, Osteology, and Paleopathologies

Osteology and Forensic
Anthropology
Reminder: Homework due one
week from today
Happy Birthday Mary Leakey!
1913-1996
Osteology
• The scientific study of bones.
• Comes from the Greek word “Osteon,” meaning
“bone”
• Sub-discipline of archaeology (anthropology),
anatomy, forensics etc.
Why should we care?
• What bones can tell us about an individual:
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Age at death
Height/stature
Biological sex
Health
Habits
Cause of death
Ancestry
Why should we care?
• What bones can tell us about a population:
– Overall health patterns
– Overall age expectancy
– Gender or class specific work patterns
“Human skeletal remains are a unique source of
information on the genetic and physiological responses
our ancestors made to the challenges posed by past natural
and sociocultural environments.” –Phillip Walker,
Bioarchaeological Ethics, 2000
Types of Bone cells
• Bone is formed and metabolized by specific
cells and is in a constant state of
remodeling.
– Osteoclasts: Bone destroying cells
– Osteoblasts: Bone generating cells
– Osteocytes: Mature bone cells; “spider” shaped,
maintains bone tissue.
The Human
Skeleton
Skull: mandible and cranial bones.
Axle skeleton: vertebral column,
clavicle, sternum and ribs, pelvic
bones.
Long bones: limbs (arms and
legs).
There are 206 bones in a mature
human skeleton.
The Human Skeleton
• Proximal v. distal
• Sagittal plane: cuts
through the body front
to back, divides body
into left and right
halves.
• Transverse plane:
divides body at the
waist into upper and
lower halves.
The Human Skeleton
The Individual
• How to determine age:
– Macroscopic:
• Changes we can see with the naked eye.
– Microscopic:
• Requires the use of a scanning microscope.
– Dental development and eruption.
• Eruption starts anterior to posterior.
• Dental development in children is very precise.
The Individual
• How to determine age:
– The growth rate of bones can tell us (roughly)
how old someone is.
• Fusion/ossification = when bones develop, or fuse.
• Osteons
– Wear on bones and teeth.
– Bones most often used: teeth, humerus, cranium
(cranial sutures), pubic symphysis .
The Individual
• How to determine age:
– Determining age really only works until about
age 65 (macroscopically).
– Cortical remodeling works as an age
determinate until about age 75 (microscopically)
The Individual
• How to determine sex:
– Determining the biological sex of subadult is
much more difficult than in mature skeletons,
and many times impossible.
– “robust” vs. “gracile” as a means of
determining male versus female.
– Bones most often used: pelvic bones, mandible,
cranium.
• Health/habits:
The Individual
– (Paleo)pathologies
– Infectious diseases of
bone
– Wear patterns on bones
– Status or class markers
• Evidence of iron deficiency anemia in cranial
bone.
The Individual
• Advanced arthritis
of the spine (lumbar
vertebrae).
The Individual
• Tooth wear and decay
The Individual
• Infectious disease:
– Although an infection my lead to death it may
not detectably alter bone. Those that do though,
often leave lesions (a few examples of diseases
which do leave a telltale mark on bone:
smallpox, leprosy, histoplasmosis)
– Osteitis: inflammation of bone due to infection.
• Wear pattern on
scapula and humerus
Also, if an individual is a weight lifter, runner, etc, that will be
represented on the skeleton as well.
Isotopic Analysis
or
You are what you eat
• Stable isotope analysis: is the analysis of stable
(nonradioactive) isotopes of elements (like carbon) that
provides information about ancient diet.
• Strontium isotope analysis: the analysis of strontium, which
come from water, to determine where an individual lived
during their lifetime.
• Isotopes: are variants of a particular chemical element
(Example: C-12, C-13, and C-14 are three isotopes of carbon
The Population
• Overall health of a
population
– Example: A Maya
population at Copan,
in Honduras,
experienced a lot of
anemia during the
late Classic and early
Post Classic periods
(750-1200). Therefore,
they were not getting
enough iron.
The Population
• Class or gender roles:
– Wear on bone can illustrate
that some jobs were more
likely men or women.
– Example: in many PreColumbian societies, the
grinding of maize (corn) was
a woman’s job. We know
this through osteological
evidence from female
skeletons.
The Population
• Indicators of status in society: for example, the
ancient Maya incised and filed teeth as a marker of
high or elite status.
The Population
• Funerary archaeology
– How and where bodies
are buried
– What artifacts are
buried with them.
– Tells us a lot about a
population.
Forensic Anthropology
Forensic Anthropology
• Forensic anthropologists apply standard
scientific techniques developed in physical
anthropology to identify human remains,
and to assist in the detection of crime.
Forensic Anthropology
• Osteological techniques as applied legal
settings.
– most often in criminal cases involving advance
stages of decomposition.
– There are not many people who identify
themselves solely as forensic anthropologists.
– http://www.physanth.org/ (American
Association of Physical Anthropologists)
– http://www.theabfa.org/ (American Board of
Forensic Anthropologists)
Cause and Manner of Death
• Cause of death: the disease or injury
responsible for the sequence of events. Very
specific.
• Manner of death: explains how the cause of
death arose (example: natural vs. violent;
accident, homicide, suicide etc).
Skeletal Trauma
• Fractures (stress,
pathological, etc)
• Blunt force trauma
• Sharp force trauma
• Projectile Trauma
Key Terms
• Postmortem: occurred after death.
• Perimortem: occurred near or at time of
death.
• Antemortem: occurred before death.
Key Terms
• Skeletal Trauma
• Remodeling
• Taphonomic changes: the process of the
archaeological record. “Taphos” = Greek for
death.
So how do we tell the difference???
Living vs. Dead bone
• In living bone the
moisture content is
high.
• Collagen (what gives
bone its elasticity) is
somewhat flexible.
• This allows for a
certain degree of
bending under stress.
• With decomposition,
moisture is lost,
collagen degrades and
the bending capability
is lost.
• Bone frails or snaps
when subjected to
trauma.
Postmortem changes to bone
• Roots.
• Tooth marks on bone. Carnivore = depressed
fractures. Rodent = line fractures.
Blunt Force Trauma
Blunt force trauma to the left
temporal bone.
• Any injury cause by a force
that has a wide are of
impact on bone.
• Usually bones with BFT
exhibit both
discontinuities and
fracture lines.
• Outbending and
inbending on crainial
injurys.
Sharp Force Trauma
• Results from
compression, shearing,
etc.
• “chop marks,”
“punctures,”
“incisions.”
• Caused by knives,
axes, ect.
• Sequence can usually
not be determined.
Projectile Trauma
• Very distinct.
• Directionality of force is
usually very clear.
• Speed is of projectile is a
factor.
• Starts small, becomes
wider as it passes through
bone. So, exit wounds are
generally larger than entry
wounds.
Projectile Trauma
• Keyhole wounds: when
projectile grazing the
bone on entry or exit.
Creates a “keyhole”
shape
Miscellaneous Trauma
• Strangulation: breaks
the hyoid bone.
• Congenital perforation
of the sternum:
Though it looks like a
bullet hole, it is
actually a hereditary
marker.
Additional Information
• Bone Voyage, by
Stanley Rhine
• Kathy Reichs
• The Bone
Woman, by Clea
Koff
• The Human Bone
Manual, by White
and Folkens