Forensic Anthropology

1. Forensic Anthropology What can it tell us?

2. Vocabulary • Anthropology – the scientific study of the origins and behavior as well as the physical, social, and cultural development of humans • Epiphysis – the presence of a visible line that marks the place where cartilage is being replaced by bone • Forensic anthropology – the study of physical anthropology as it applies to human skeletal remains in a legal setting • Joints – locations where bones meet • Mitochondrial DNA – DNA found in the mitochondria that is inherited only through the mother • Ossification – the process that replaces soft cartilage with hard bone by the deposition of minerals

3. Vocabulary • Osteobiography – the physical record of a person’s life as told by his or her bones • Osteoblast – a type of cell capable of migrating and depositing new bone • Osteoclast – a bone cell involved in the breaking down of bone and removal of wastes • Osteocyte – an osteoblast that becomes trapped in the construction of bone; a living bone cell • Osteoporosis – weakening of bone that may happen due to lack of calcium in the diet • Skeletal trauma analysis – the investigation of bones and the marks on them to uncover a potential cause of death

4. What will we cover? • How bone is formed • Distinguish between male and female skeletal remains based on skull, jaw, brow ridge, pelvis, and femur • Describe how bones contain a record of injuries and disease • Describe how a person’s approximate age could be determined by examining his or her bones • Explain the differences in facial structures among different races • Describe the role of mitochondrial DNA in bone identification

5. History • 1800s – scientists began using skull measurements to differentiate human bodies • 1897 – Luetgert murder case; man killed his wife and boiled down her remains • Fragments of skull, finger and arm found • 1932 – FBI opened first crime lab helping identify human remains • 1939 – William Krogman published Guide to the Identification of Human Skeletal Material

6. History Cont’d • WWII – remains of soldiers identified using anthropological means • Recently – new mitochondrial DNA techniques have identified Romanov family skeletal remains

7. Development of Bone • Bones originate from osteoblasts • Begin in fetus as soft cartilage • Osteoblasts harden (ossificate) during first few weeks of life to become bone

8. Development of Bone • All of our lives – bone is deposited, broken down and replaced • Osteocytes – cells that form basic framework for new bone

9. Development of Bone – Functions of Osteoclasts • Osteoclasts – • Specialized to dissolve and shape bone as you age • Also help maintain homeostasis of calcium • Dissolve bone when calcium is needed and release into blood • Can lead to osteoporosis • When bone is injured – secrete enzymes that dissolve broken bone so new bone can be laid down

10. Number of Bones • Children – 450 • Children have bones that eventually suture together • Adult – 206 after all bones have fully developed

11. How Bones Connect • Joints – locations where bones meet • Three types of connective tissue • Cartilage – wraps ends of bones for protection and to keep from scraping • Ligaments – bands of tissue that connect two or more bones • Tendons – connect muscle to bone

12. Aging of Bone • What can bone tell us? • Children build bones faster and bones grow in size • After 30 years – process starts to reverse and bones deteriorate faster than built • Can be slowed by exercise • # of bones and their condition can tell a person’s age, health, and calcium in food

14. Osteobiography • The story of a life as told by bones • Things we can see: • Loss of bone density, poor teeth, signs of arthritis • Previous fractures, artificial joints, and pins • Right-handed vs. left-handed • Physical labor

15. Surface of Bones • Males vs. Females • Males – appearance usually thicker, rougher, bumpy • Due to muscle connections, bigger body size • Females – smoother (gracile) and less knobby (robust)

16. Skulls – Bones to Know • Maxilla • Mandible • Zygomatic bone • Vomer bone • Frontal bone • Nasal bone • Orbit (eye socket) • Sphenoid bone • Sutures (between skull bones)

17. Skulls – Male vs. Female Frontal View

18. Skulls – Male vs. Female Side View

19. Male Vs. Female Skull

20. Pelvis – Anatomy • Bones to Know • Ilium • Ischium • Pubis • Sacrum • Coccyx • Pubic symphysis • Obturator Foramen

21. Pelvis – Male vs. Female • Things to consider: • Sub-pubic angle • Length, width, shape, angle of sacrum • Width of ileum • Angle of sciatic notch

22. Pelvis – Male vs. Female

24. Pelvis – Male vs. Female • Other differences in female pelvis: • Often weighs less • Surface engraved with scars after female has given birth • Can be detected most at pubic symphysis • Thigh Bone: Femur • Angle of femur to pelvis is greater in females and straighter in males • Male femur is thicker than female femur

25. Distinguishing Age • Bones don’t reach maturity at the same time – To help tell their age: • suture marks • presence or absence of cartilage

26. Suture Marks • Zigzag areas where bones of the skull meet • In babies, some is soft tissue that is gradually ossified • Suture marks slowly fade to give smoother appearance as bones age

27. Suture Marks Cont’d • Coronal Suture: • closed by age 50 • Lamboidal Suture: • begins closing at 21 • accelerates at 26 • closed by 30

28. Cartilaginous Lines • Epiphysis – line that forms as cartilage is replaced by bone • Also called Epiphyseal plate • Line disappears as bone completes growth • Presence or absence of this can approximate age

29. Long Bones • When head of a long bone has fused with shaft completely – indication of age • Each bone takes different amount of time

30. Long Bones Chart

31. Long Bones Chart 2

32. Estimating Height • Measuring long bones like femur or humerus can help estimate height • Databases established that use mathematical relationships • Different tables for males, females, and races • Example • A femur measuring 49 cm belonging to an African American male is found. Calculation: 2.10(length of femur)+72.22 cm 2.10(49) + 72.22= 175.12 cm or 69 inches (5’9”)

33. Distinguishing Race • This is losing its significance in differences • Two biggest differences are in skull and femur: • Shape of eye sockets • Absence or presence of nasal spine • Nasal index – width of nasal opening X 100 height of nasal opening • Prognathism – projection of upper jaw (maxilla) beyond the lower jaw (mandible) • Width of face • Angulation of jaw and face

35. Distinguishing Race

36. Other things bones can tell • Left or right-handed • Diet and nutritional dairy, esp. vit D and calcium • Diseases or genetic disorders: • Osteoporosis, arthritis, scoliosis, osteogenesis imperfecta • Type of work or sports based on bone structure • Previous injuries such as fractures • Surgical implants: artificial joints, pins • Childbirth

37. Facial Reconstruction • Theoretically possible to build a face from skeleton up using clay • Related to size and shape of muscles and tissues that overlay bones • Specific markers on face are used • Reconstruction attempted on • Johann Sebastian Bach • King Tut • Same techniques used to age missing persons • http://science.howstuffworks.com/body-farm.htm

38. Reconstruction of Bach

39. DNA Evidence • Mitochondrial DNA degrades much, much, much slower • Can be extracted from bones and compared to living relatives on mother’s side of family

40. Skeletal Trauma Analysis • Forensic scientists trained to recognize marks made by weathering and animals • A knife wound on rib leaves a mark that might look similar to rodent chew marks • Goal is to tell the difference in marks made by patterns in weapons, and marks made by weathering • Forensic anthropologists try to determine cause of death and weapon

41. Skeletal Trauma Analysis • Sharp-force and blunt-force trauma, gunshot, and knife wounds all have distinctive patterns • Living bone flexible compared to old and brittle bone • Bones break differently when living versus when old