1. Forensic Anthropology
Chapter 13

2. Skeleton WS: How many bones do you know?

3. Answers: Learn these ASAP!!

4. Anthropology
Anthropology: study of the origin, behavior, and the physical, social, and cultural development of humans
Forensic Anthropology: studies identifying characteristics on human skeletal remains
Can determine: sex, race, height, physical health

5. With a single bone…
A forensic anthropologist may be able to determine….
The approximate size (height)
The sex of the individual
If the remains are human or nonhuman
The approximate age
The race of the individual
Injuries before, during and after death

6. What does your skeleton do for you?
Lever for the body – Provides support
Protects internal organs
Moves the body
bones + muscle = movement
Stores minerals (Calcium and Phosphorus)
Formation of blood cells
red marrow found in bone cavities of infants; spongy bone of skull, ribs, sternum, clavicle, vertebrae and pelvis.
Storage of fat cells
yellow bone marrow found in the bone cavities.

7. Characteristics of Bone: Are bone cells alive?
Bones are alive.
Their cells consume energy using cellular respiration.
Capable of growth and repair.
The amount of calcium in the hard part of the bone is regulated by hormones.
Bone marrow: interior of bones; where RBCs & lymphocytes (WBCs) are made.
Periosteum: protective membrane layer containing nerves and blood vessels that covers the surface of bones.
Keeps bones moist and aids in repair.

8. Development of Bone
Osteoblasts: cells that migrate and deposit new bone
In a fetus, bones begin as soft cartilage.
Osteoblasts deposit calcium phosphate that causes hardening into bone.
Osteocytes (living bone cells): osteoblasts that become trapped, forming the framework of the new bone.
Ossification: mineral deposits that aid in the hardening of cartilage into bone.

9. Development of Bone (cont’d)
Osteoclasts: specialized cells that secrete enzymes to dissolve bone.
Functions:
Reshape bones as they grow
Remove cellular wastes & debris
Repair broken bones
Maintain calcium homeostasis in blood
When calcium in the blood is low, osteoclasts dissolve bone to release calcium.
If not enough Ca in diet, can lead to osteoporosis (weakening of bone).
Osteoclasts,
Osteoblasts, & Osteocytes

10. Microscopic Images Osteocytes – are mature bone cells
Haversion canals surrounded by lacunae (rings)

11. Number of Bones 206 bones in an adult
450 bones in a baby (fuse together as person develops)

12. X-ray of a newborn baby.
Gaps between bones indicate cartilage.

13. Bone continues to form and change in adulthood – bones get harder in response to stress and injury.

15. an inorganic, mineral component
What is Bone??
It consists of a dense organic matrix (living osteons and blood vessels)
and
an inorganic, mineral component
(Ca, K and P).

16. What is Bone?? Epiphysis- The ends of a (long) bone
Diaphysis- The weight bearing portion, the shaft.
Epiphyseal plate- region where epiphysis and diaphysis connect. Great for determining age!

17. What is Bone??
Spongy bone- region with many spaces and full of red marrow
Compact bone- region of bone very dense, capable of bearing a lot of weight or strain.
Yellow marrow- fat storage
Red marrow- region of red blood cell production (in infants)

18. Joints Between Bones Joint: the location where bones meet (articulate)
Three Types of Connective Tissue:
Cartilage: wraps the end of bones to prevent scraping.
Ligament: connects two bones
Tendon: connects muscle to bone

19. What Can Bones Tell Us?
Osteobiography: bones can tell us about a person’s life
Handedness – bones will be slightly larger on the hand that is used more.
Physical Activity/Sports – wear on bones & size of bones
Health/Nutrition – bone density (calcium), teeth, arthritis
Forensic Analysis
Age – fusing of bones, bone density
Sex – pelvis & skull
Height – estimate from long bones
Race – skull characteristics

20. SORTING BONES

21. Sorting Bones…. Long bones
longer than wide, long shaft (diaphysis) bulky ends
Primarily compact but with spongy at the ends
Can extract height and general frame size from these bones
Examples: femur, tibia and fibula. Humerus, radius and ulna.

22. Sorting Bones…. Short bones cube shaped, mainly wider than long
Examples: Tarsals, carpals, patella

23. Sorting Bones…. Irregular bones Thin, flat and often curved.
Mainly spongy
Examples: vertebrae, mandible, hyoid, sacrum, coccyx.

24. Sorting Bones…. Flat bones Mainly spongy with a thin layer of compact
Examples: Skull plates, sternum, scapula, ribs, ilium

26. Human vs. Non-human

27. Human or nonhuman bone?
A human's tibia and fibula (foot) and radius and ulna (wrist) are separate bones.
Animal bones are denser and less porous when viewed as a cross section.

28. Human or nonhuman bone?
Animal femurs are usually about the same length as the other limbs.
Humans have four curves to the spine, animal spines are relatively straight
Animals generally have a V-shaped jaw that separates at the midline.
Humans have flat teeth, animals have fewer teeth and larger canines.

29. Human or nonhuman bone?
...these bones are not human.
This clawless hind paw of a black bear looks somewhat like a human foot.

30. Determining Height

31. Estimating Height
Can use long bones (humerus, femur, etc.) to estimate height.
Separate tables for male, female, different races

32. Example Problems Estimate the height of the person:
African American female ulna of 25.6 cm.
Stature = (3.31 x ulna) cm = (3.31 x 25.6) cm = 160 cm
To convert cm into feet: 1 foot = cm
160 cm x 1 foot = feet cm
0.249 feet x 12 inches = 3 inches => 5’ 3” foot
Estimate the height of a male with a tibia of 40 cm.
179 cm (5’ 10”)

33. Determining Sex

34. Determining the sex of the individual…
Angle/width of pelvis
Jaw line
Ridge brow/slope of
forehead
Angle of femur
Sciatic notch

35. Determining Sex Overall Appearance of Skeleton:
Female – smoother, less knobby => gracile
Male – thicker, rougher, bumpy => robust
Why? Male hormones lead to bigger muscles & larger attachment sites on bones.

36. Determining Sex: Pelvis
Pelvis Characteristic
Male
Female
Subpubic angle
50o – 82o (less than 90o)
90o or greater
Pelvic cavity
Heart-shaped
Oval-shaped
Sciatic notch
Narrow
Wide
Ilium
Tall, narrow
Short, wide
Sacrum
Narrow, tall, curved into pelvic cavity
Wide, short, straight
Pubic symphysis
No scars
Scars (if childbirth)
Shape of pubis
Triangular
Rectangular

37. Pelvis Characteristics

38. Male or Female? Why?

39. Determining Sex: Skull
Skull Characteristic
Male
Female
Eye orbit
Square
Rounded
Chin
V-shaped
Brow Ridge
Large
Small
Occipital protuberance
Nuchal Crest
Frontal bone
Low, sloping
High, rounded
Mandible Angle
Square (90o)
Sloped (>90o)
Mastoid process

40. Female Male

41. #1 – Females have a less pronounced brow ridge and a more vertical angle to the forehead than males.
#2 – The mastoid process (jaw) is much more visible in males.
#3 – The nuchal crest is rounded in females and has a sharper, more pronounced angle in males.

42. 1) Male or Female? Why? B A
2) Male or Female? Why? A B

43. Is this skull Male or Female? Why?

44. Determining Sex: Femur
Female: angle of femur is greater
Male: femur is straighter

46. Determining Race

47. Determining Race
Becoming more difficult with more intermarriage between races.
Skull
Shape of eye sockets
Absences or presence of nasal spine
Nasal Index
(width/height of nasal opening x 100)
Prognathism
Width of face
Angulation of jaw and face

48. Distinguishing Races

50. DNA Evidence from Bones
Bones contain very little nuclear DNA that is used for DNA profiling.
Bones do contain mitochondrial DNA
Contains only maternal information, but mtDNA long outlasts nuclear DNA in bones.

51. Determining Age

52. Determining Age Suture: zigzag appears where bones meet
Lambdoidal suture starts closing at 21, accelerates at 26, closed by age 30
Sagittal suture closed by age 32
Coronal suture closed by age 50

53. General Aging of Bones
Children build bones at a faster rate than the rate the bones are breaking down.
After 30 years, bones deteriorate faster than they are produced.
Deterioration can be slowed by exercise.
Bones can become frail, less dense, and porous  osteoporosis
Number of bones and their condition can tell a person’s age, health & amount of calcium in diet.

54. Estimating Age
Presence of Epiphysis: a visible line that marks the place where cartilage is being replaced by bone
Head of long bones fusing to shaft

55. Age Estimates

56. Skeletal Trauma

57. Skeletal Trauma Analysis
Bones left outside are subject to:
Weathering
Rodent chew marks
Skeletal Trauma Analysis – investigation of the marks on bones to uncover potential cause of death
Sharp vs. Blunt force – Blunt has more cracks radiating from the site of impact, more damage to the surface of the bone
Gunshot
Fracture in living bones – shatter in spiral pattern parallel to length
Fracture in nonliving bones – break perpendicular to length

58. Facial Reconstruction
Used to ID victims of explosions or blunt force trauma
Facial Reconstruction – rebuilding a face from skull measurements
Uses facial markers at critical locations.
Clay is molded to follow the height of the markers.
Video-Superimposition – image of skull created and is compared to photograph.

59. Facial Reconstruction (cont’d)
1st Facial Reconstruction (1895) – Wilhelm His used the skull of Johann Sebastian Bach to reconstruct his face in clay.
Reconstruction of Egyptian King Tutankhamen (King Tut).