Forensic Anthropology What can it tell us?

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

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

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

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

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

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

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

Development of Bone – Functions of 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

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

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

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

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

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)

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

Skulls – Male vs. Female Frontal View Trait Female Low and sloping Frontal Bone Higher and more rounded More Square Shape of Eye (orbits) More Rounded Mandible (Lower Jaw) More V-shaped Thicker and larger Upper Brow Ridge (Zygomatic) Thinner and smaller

Skulls – Male vs. Female Side View Trait Female Present Occipital protuberance Absent Lower and more sloping Frontal bone Higher and more rounded Bumpy and rough Surface of skull smooth Angled at 90° (straight) Mandible (Jaw bone) Greater than 90° (sloping)

Male Vs. Female Skull

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

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

Pelvis – Male vs. Female Male Trait Female 50-82 degrees Subpubic angle > 90 degrees Triangular pubis Shape of pubis Rectangular pubis Heart shaped Shape of pelvic cavity Oval shaped Longer, narrower, curved inward sacrum Shorter, broader, curved outward

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

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

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

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

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

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

Long Bones Chart Region of Body Bone Age Arm Humerus bones in head fused 4-6 Humerus bones in head fused to shaft 18-20 Leg Femur: greater trochanter appears 4 Lesser trochanter appears 13-14 Femur: head fused to shaft 16-18 Femur: condoyles join shaft 20

Long Bones Chart 2 Region of Body Bone Age Shoulder Sternum and clavicle close 18-24 Pelvis Pubis, ischium completely united 7-8 Ilium, ischium, pubis fully ossified 20-25 All segments of sacrum united 25-30 Skull Lamboidal suture closed 21-30 Sagittal suture closed 32 Coronal suture closed 50

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”)

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

Distinguishing Race Caucasoid Negroid Mongoloid Shape of Eye Orbits Rounded, somewhat square Rectangular Rounded, somewhat circular Nasal Spine Prominent spine Very small spine Somewhat prominent spine Nasal Index <.48 >.53 .48-.53 Prognathism Straight Prognathic Variable Femur Fingers fit under curvature of femur Fingers don’t fit under curvature of femur

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

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

Reconstruction of Bach

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

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

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