Transcript Bone

Chapter 13 Forensic
Anthropology:
Dead Men do Tell Tales
Anthropology and
Crime
Kathy Reichs- Bones
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Historical Development
1. In the 1800s, scientists began studying skulls.
This laid the framework for today’s knowledge.
2. In 1932 the FBI opened the first crime lab.
3. The Smithsonian Institution became its working
partner in the identification of human remains.
4. Soldiers killed in World War II were identified
using anthropologic techniques.
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Development of Bone
 Bones originate from cells called osteoblasts.
 They migrate to the center of cartilage
production and deposit minerals.
 Throughout life, bones are being broken
down, deposited, and replaced.
 Osteoclasts, the 2nd type of bone cell, among
other tasks, remove cellular wastes.
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How Bones Connect
 Bones are held together by:
a. cartilage—wraps the ends of bones and
keeps them from scraping one another.
b. ligaments—bands that connect two or
more bones together.
c. tendons—connect muscle to bone.
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As long as cartilage is present bones can still
grow
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Females- grow till 18
Males – grow till 20-21
18-30 years old- bone loss= bone mineral
deposit
After 30 – bone loss exceeds deposits
(bones shrink) , can lessen with exercise
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What Bones Can Tell Us
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Osteobiography tells much about a person
through the study of the skeleton.
 The bones of a right-handed person, for
example, would be slightly larger than the
bones of the left arm.
 Forensic scientists realize that bones contain a
record of the physical life.
 Analyzing bones can reveal clues to such
things as gender, age, height, and health.
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Gender - Skull
 Female skull is rounder and smaller than
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males
 Female forehead is longer vertically and jaw
is smaller
 Male jaw is square with an angle of 90
degrees
 Occipital protuberance (bony knob on base of
skull)on males is larger
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Gender - Pelvis
 The surface of a woman’s pelvis can be
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scarred after childbirth
 The sub pubic angle of the female pelvis is
greater than 90o, ;lighter and smoother, the
male’s, less
 Female tailbone (coccyx) is more flexible
 Woman’s pelvic girdle is wider
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Pictures
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http://anthropology.si.edu/writteninbone/comi
c/activity/pdf/skeleton_male_or_female.pdf
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Age
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By about age 30, the suture at the back of the
skull will have closed.
By about age 32, the suture running across the
top of the skull, back to front, will have closed.
By about age 50, the suture running side to side
over the top of the skull, near the front, will have
closed.
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Age
 During life, many of the 450 bones a person has
at birth grow together, finally forming 206 bones.
 As the cartilage between them is replaced, an
epiphysis line is visible.
 When the cartilage is fully replaced, the line is no
longer visible.
 Ends of sternal rib bones are rounded in young
adults, jagged and cup shaped w/ age
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Age- Teeth
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Look for eruption of baby teeth or permanent
teeth (occurs at regular intervals- very
accurate
Loss of permanent teeth associated with old
age
Teeth wear occurs w/ age and more dentine
(yellowing) is exposed with loss of outer
white tooth enamel
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p,. 15-16 Teeth Eruption (can look through
other pages for female/male/ age charts)
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Height
 An estimate of height can also be made by
looking at arm and leg bones.
 Often, the approximate height of a person
can be calculated from one of the long bones
even if just one of those is found. (formulas
on page 371)
 Gender and race will need to be taken into
consideration in making the estimate.
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Race
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Classify into three categories: Caucasoid
(includes European, Italian, Arab, Indian),
Negroid (African, Jamaican) , Mongoloid
(Asian, American Indian, Alaskan, Hawaiian,
South American)
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General Race Characteristics
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Race
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In the absence of DNA, can you really
determine race from a jawbone?
Probably not.
If you place an Asian jawbone on a table, the
bottom of it will likely maintain contact with
the tabletop all the way around. African and
Caucasian mandibles, in contrast, tend to
undulate, or rise and fall along the lower
border.
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Race
The gonia—that's the area beneath your ears where
the jawbone turns upward—generally curve more
sharply in an Asian jaw.
 People of African descent often have slightly curled
surfaces on the rear edges of their jaws, whereas
European jaws are more likely to have a flatter edge.
 Racial classification is an inexact science, if that's
even the right word for it. Forensic anthropologists
never make definitive ancestry pronouncements.
They say a bone is "consistent with" European
ancestry or "likely" of Asian ancestry.
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Article: Scientists disagree
between race and bones
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http://abcnews.go.com/Technology/t/story?id
=98485&ref=https%3A%2F%2Fwww.google.
com%2F
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Facial Reconstruction
(how its made-facial)
http://www.youtube.com/watch?feature=endscreen&v=6G0LvImAGAg&NR=1
 *A face is formed by the skull with the muscles and
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tissues on top of the skull.
*Theoretically, nonetheless, a face can be rebuilt
from just skeletal remains.
*Facial markers are positioned at critical locations
on a skull, and clay is contoured to follow the
height of the markers.
Today, computer programs perform a similar
function.
These computer programs also can age missing
persons and criminals.
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DNA Evidence
 *Bone contains little nuclear DNA.
 *But it does contain mitochondrial DNA.
 *This has DNA that is inherited only from the
mother.
 Long after nuclear DNA has been lost through
tissue degeneration, mitochondrial DNA can be
obtained from bone.
 Results can be compared with living relatives on
the mother’s side of the family to identify skeletal
remains.
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Skeletal Trauma Analysis
 *Forensic anthropologists often determine if
damage to bones occurred before or after
death.
 Definite distinctions exist between patterns on
bones made by weapons and the patterns
created by the environment after death.
 Sharp-force trauma, blunt-force trauma,
gunshot wounds, and knife wounds all have
distinctive patterns.
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. . . . . . . . . . Summary . . . . . . . .
 Bones are live and carry on all life functions.
 The condition of bones can tell investigators
about a person’s health and nutrition during
life.
 Male and female skeletons differ in many
ways.
 The age of a person at death can be estimated
by analysis of a number of bones.
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. . . . . . . . . . . . . . . . . Summary
 A person’s height can be estimated by the
length of long bones.
 Facial reconstruction is possible to some
extent.
 Mitochondrial DNA can be extracted to help
identify skeletal remains.
 Skeletal trauma analysis examines bones for
evidence of damage.
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CSI- Murfreesboro
Bone –gunshot (bill bass)
Smithsonian
Bone Detective (56 min lectureanthropologist)-start 15 min in
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Bone Height
– Caucasion:
– Male:
3.76 x length ulna (cm) +
75.55 (+ or – 4.72)
– Female: 4.27 x length ulna (cm)
+ 57.76 (+ or – 4.30)
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Height Lab
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Purpose
Part 1: Ulna bone length, predicted height with
formula, actual height converted to cm and % error
Part 2:
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Data table 1- convert actual height to cm,
Data table 2 – measure ulna bone, using formula predict
height, do % error,
Graph (of actual height (data table 1) vs ulna bone
length (data table 2)
Questions (including your predicted height using
graph and % error)
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Vitruvian man video- BBC (15 min)
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