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| Forensic
Anthropology |
| When bones or skeletons are found,
they are taken to a forensic laboratory for examination. The job of
an anthropologist,
a forensic scientist specializing in the area of bones, is to examine
the bones, to possibly deduce the gender, age, height, race, as well
as medical history and manner of death. |
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Select one of the following topics to read more:
--> The
basic task
--> Growth
rate
--> Gender
--> Height
--> Bone
defects
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| The
Basic Task |
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| The first step an anthropologist takes
during the examination of bones, is to find out whether the bones
are human or animal, as sometimes certain animal bones will resemble
that of human bones. Once this has been determined, the next step
is finding the age of the bones by noting the growth and decay that
has occurred in the bones. |
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| Growth
Rate |
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Teeth that have or have not grown can also reveal the age of the
skeleton, as young children will have not lost their milk teeth
and at the age of 18, wisdom
teeth first appear. During the teenage years, bones become
thicker and larger and fuse together in a process known as 'ossification'.
Ossification occurs in 800 points of the body and is the best guide
to revealing the age of a child's skeleton. An example of ossification
occurs in the arms, where at the age of six, the two bone plates
form at either end of the outer forearm (radius).
At the 17 in males and 20 in females, the lower bone plate and
the radius
fuse together and soon after, the upper bone plate and radius fuse
together. The bone in the body that finishes growing last is the
collarbone,
which ceases growth at 28 years. In the bones of the elderly, degeneration
begins to occur. Anthropologists will look for tiny spikes that
start to appear on the edges of the vertebrae,
the wearing of teeth due to age and joints that show signs of arthritis.
All of the bones in the body will deteriorate with age.
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| Gender
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| When determining male and female
in a skeleton, anthropologists look at the skull and hip bones, as
there lie clues to the sex of the skeleton. The skull has three points
in determining gender. These are the ridges located above the eyes,
the bone situated just below the ear and the occiput,
the bone located at the lower back of the skull. The latter two bones
are muscle attachment sites, all of which are more prominent in men,
indicating greater strength. The difference in hips is very obvious,
as a man's hip are narrower and a women's hips are wider, being built
for child bearing. However there are smaller differences in other
bones, which anthropologists rely on when there is no hip or skull
bone. |
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| Height |
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| Determining the height of a skeleton
involves reassembling the skeleton and measuring the length of significant
bones. By adding 10-11cm or four inches onto the bone length, it accounts
for the missing tissue
and muscle. If parts of the skeleton are missing, certain individual
bones are used as a height guide. The longer the bone is, the better
and more accurate the estimate will be, so the femur is measured first.
The human height measures roughly two and two thirds the length of
the femur,
though it also depends on the race and sex of the skeleton. |
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| Bone
Defects |
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| Disease, injury and birth defects
are also revealed in the bones. Birth defects such as spina
bifida, some infectious diseases, poor diet and cancer can
all be damaging to the bones. In the case of injuries, broken bones
and mended bones are easily visible and because they are so easily
visible, mended bones can reveal identity. Work and hard labour leave
damage such as occupational arthritis,
which visibly changes the appearance of affected joints. The skeletal
remains of someone who has died a particularly violent death are evident
in the bones. Bullet wounds leave round holes, sharp weapons cause
chips to be taken out of the bone and fractures in the bones also
suggest forms of violence. Distinguishing between fractures that occurred
before and after death is difficult, but there are some clues that
are helpful. For example, the bones of a deceased person break differently
compared to the bones of a live person and healing at the edge of
a fracture indicates injuries during life. |
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