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| 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). |
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Comparison of a 5 yr to a 60 yr old skull. Photo
courtesy of Valeri
Craigle and the Spencer
S. Eccles Health Sciences Library |
| 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. |
| *The
space between the hips of a woman are much larger
than that of a man. Photo courtesy of Valeri
Craigle and the Spencer
S. Eccles Health Sciences Library |
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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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The wire left in bone to repair a fracture may give
away the unknown identity. Photo courtesy of Valeri
Craigle and the Spencer
S. Eccles Health Sciences Library |
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