Forensic anthropology

BONES

• Forensic Anthropology is a specialized area of anthropology (study of humankind) that studies the human skeleton and how it has evolved throughout history.

• In 1939 the FBI published “guide to the Identification of Human Skeletal Material”

• In 1948 Mildred Trotter organized a laboratory to examine bones of dead soldiers to identify them and return them to their families

• Trotter also created new structural charts and mathematical tables to aid in identification

• In 1979, the first forensic anthropology textbook was written by Dale Steward (former curator of anthropology at the Smithsonian Institution

• In Europe in the 1800s, scientists began using skull measurements to differentiate among individuals. Differences between male and female anatomy, formation, aging, and fusing of bones were examined.

• Leutgert murder case of 1897 – a man was accused of killing his wife and boiling down her corpse. Remains found appeared to fragments of his wife’s skull, finger, and arm.

• 1932 – FBI announced the opening of its first crime lab and the Smithsonian became a working partner, aiding in identification of human remains

• 1939 – William Krogman published the Guide to the Identification of Human Skeletal Material

• Remains of soldiers killed during World War II were identified using anthropologic techniques

• New techniques in mitochondrial DNA have been used in identification of skeletal remains

Examination of recovered bones can revealwhether bones are human, age, height, sex, injuries, nature of wounds, history of accidentsand medical conditions.

• Bones originate from cells called osteoblasts.• Ossification – the process that replaces soft cartilage with

hard bone by the deposition of minerals• By the 8th week of pregnancy, the outline of the skeleton

has formed and is visible in an X-ray• As bone develops, a protective membrane layer that

contains nerves and blood vessels covers the surface of the bone. This membrane, called the periosteum, serves an important role in keeping bones moist and aiding in the repair of injuries

• A baby has 450 bones, an adult has 206!

• Human bones can be distinguished from other species based on their size, shape, and structure.

• The number of individuals that are present as skeletons can be determined by looking for duplicate bones, and by looking for differences in age, size, structure and preservation.

• DNA analysis of bones can identify if the bones are from the same individual or if multiple individuals are present

• Throughout our lifetime, bones are being produced and being broken down.

• Children build more bones at a faster rate than the rate of bones being broken down. As a result, the bones grow!

• After 30 years, the process begins to reverse and bones are broken down faster than they are built.

• The number of bones and their condition can tell an investigator about a person’s age, health, and whether they had enough calcium in their food

• Children are easier to analyze because of skeletal growth is very well-documented and bones fuse at very regular rates

• After puberty, it is often impossible to tell the age

• Suture Marks - Suture marks with a zigzag appearance are found on the skull where bones meet. In an immature skull, areas of softer tissue gradually become ossified (harden). The suture marks slowly disappear as the bones mature.

• Cartilaginous Lines - We are born with more than 450 bones that later join together to form 206 bones. As the cartilage is slowly replaced with hard, compact bone, a cartilaginous line is visible, called an epiphysis. When the cartilage is fully replaced, a line is no longer visible.

• Long bones - When the head of a long bone, like the thigh or upper arm bone, has totally fused to its shaft, it is another indication of age.

Because this fusing occurs at different times with different bones, this information can be

used to approximate age.

• It is difficult to determine the sex of children because many changes in skeleton are apparent after puberty

• Pelvis of a female is usually wider than male to accommodate a baby

• Skulls:– Males have a more square chin– Male foreheads protrude further than female

(how long ago the individual died) depends on several factors such as:

• temperature of environment • presence of animal scavengers• humidity• rainfall• depth of burial• weight and build of individual• clothing or other wrapping• insect activity

Cranial Index = Cranial Width (cwt) x 100 Cranial Length (clt)

Nasal Index = Nasal Width (nwt) x 100Nasal Height (nht)

Orbit Index = Orbit Height (oht) x 100Orbit Width (owt)

• Vertebrae that is often fractured during strangulation

Robusticity Index = micf x 100

hltHlt = full heightMicf = minimum

circumference

Scapular Index =Scapular Width (swt) x100Scapular Length (Slt)