Objective Describe Forensic Anthropology and how it is used to solve crimes.

Warm-Up: Video http://www.hulu.com/watch/474025#i0,p0,d0 As you watch the video, write down key words/identifiers of victim’s age.

Forensic Anthropology Let the bones tell the story! Image: http://upload.wikimedia.org/wikipedia/commons/4/4c/Punuk.Alaska.skulls.jpg Presentation developed by T. Trimpe 2010 http://sciencespot.net

What role do anthropologists play in solving crimes? Watch the video and then answer the questions. What does a physical anthropologist investigate? What four things do we want to know about a skeleton? What bones are most useful for developing a profile of a person? Explain how they are used.

HOW MANY BONES ARE IN THE ADULT HUMAN BODY? 206

What is bone? Living tissue made of cells within a matrix of protein (mostly collagen) and minerals (calcium and phosphorous) The skeleton is one part of the body that takes the longest to decay Bones can last for 100s to 1,000s of years Source: http://anthropology.si.edu/writteninbone/bone_basics.html

Simple Composition of Bones Outer layer: smooth, compact bones Inner layer: spongy, porous bone Bone Marrow – responsible for producing red & white blood cells Red blood cells carry oxygen to our muscles and organs; white blood cells are responsible for fighting bacteria. Stores and releases fat for energy when needed. Left femur (thigh bone), coronal section Image courtesy of: Smithsonian National Museum of Natural History Source: http://anthropology.si.edu/writteninbone/index.htmlcc

More Accurate Composition of Bones Clues for determining age lie within the Epiphysis: Articular Cartilage – protects bones from rubbing against one another – arthritis occurs when the bone molds with the cartilage and bones begin to rub against each other. Diaphysis doesn’t have cartilage Source; http://www.bbc.co.uk/schools/gcsebitesize/pe/appliedanatomy/2_anatomy_skeleton_rev4.shtml

Determining Age - Epiphysis Ossification of cartilage creates bone Calcium is used to turn cartilage into bone – once you are done growing, you have a denser bone in the epiphysis Source: http://www.bbc.co.uk/schools/gcsebitesize/pe/images/bone_growth.gif

Technology for Determining Age An x-ray image (radiograph) of a child will reveal a dark area where the growth plates are still made of cartilage (more x-rays can pass through cartilage, which is less dense, thus making a dark area); these areas are the epiphyseal plates.  An x-ray radiograph of an adult will reveal a white area where the growth plates have been turned into bone (fewer x-rays can pass through bone, which is more dense, thus making a white line); these areas are the epiphyseal lines. 

Circle the Appropriate Answer Epiphyseal Plate   or   Line Adult   or   Child

Facts about Aging Normal growth stops around Age 17-25 Clavicle is last bone to stop growing (age 25) Tibia completes growth by: Age 16-17 (female) Age 18-19 (male) Clavicle. Image courtesy of: Smithsonian Institution Source: http://anthropology.si.edu/writteninbone/index.htmlcc

Determining Age Children Adults Teeth are best age indicator Higher presence of cartilage in epiphysis Length of long bones is good indicator for estimation of age Pelvis best age indicator Cranium, pubic bone and rib ends hold information to determine age Osteons – smaller osteons Cranial sutures Arthritis Source: http://anthropology.si.edu/writteninbone/index.html

Like Fingerprints… just can’t be seen until antemortem Examine the image below to see how the fontanels, described above, grow and fuse with the other bones to form the sutures.  Although these sutures are as unique as fingerprints, as they cannot be seen antemortem (not without surgery, or a violent accident), they are not useful in terms of identification.

Circle the Appropriate Answer Adult skull has no remaining suture (called the frontal suture) in the middle of the Frontal bone.  Remember, also, that all the sutures ultimately become more filled-in ("closed") as we age. Circle the Appropriate Answer Frontal Suture Present   or   Absent Other Sutures "Open"   or   "Closed" Adolescent   or   Adult

Male or Female? Male Female Narrower, heart-shaped pelvic inlet Narrower sciatic notch Narrower angle where the two pubic bones meet in front Open, circular pelvic inlet Broader sciatic notch Wider angle where the two pubic bones meet in front More outwardly flared hip bones Female [Left] Male pelvis. [Right] Female pelvis. Image courtesy: Smithsonian Institution Source: http://anthropology.si.edu/writteninbone/index.html

Gender- Pelvis

Try it out Angle > 90 degrees or < 90 degrees Sacrum Forward   or   Backward Pelvic Outlet Small   or   Large Ilia Close   or   Spread Female   or   Male

Gender Differences in the Skull Landmarks Female Male Chin Rounded Square Mastoid Process (Behind Ear) Small Large External Occipital Protuberance (Back of Skull) Small (Not Prominent) Large (Prominent) General Anatomy Gracile (i.e., Graceful) Robust Forehead Vertical Receding (Careful with the comments . . .) Brow Ridges (Location of Eyebrows) Slightly Developed Prominent Muscle Lines Orbital Margins (Edge of Eye Socket) Sharp Angle of Ascending Ramus (Back Corner of the Jaw) Obtuse Close to 90 degrees

Circle the Appropriate Answer Chin Rounded   or   Square Mastoid Process Small   or   Large Occipital Protuberance Small   or   Large General Anatomy Gracile   or   Robust Forehead Vertical   or   Receding Brow Ridges Slight   or   Prominent Muscle Lines Slight   or   Prominent Orbital Margins Sharp   or   Rounded Angle of Ramus 90 degrees   or   Obtuse Gender Female   or   Male Gender Female   or   Mal

Main Characteristics: Which skull would belong to a female? FORENSIC ANTHROPOLOGISTS analyze skeletal remains to determine the identity of a victim as well as his/her life history, cause of death, or other clues about a crime. Main Characteristics:  Sex - Determined by examining the skull, pelvis, humerus, and femur Age and stature (height/build) – Determined by analyzing the development of the teeth, bone growth, cranial suture lines, and the length of specific bones, such as the femur.  Race – Determined by analyzing the skull for characteristics that are common among people of different races. Which pelvis would belong to a female? Career Connection What does a forensic anthropologist do? Source: http://www.crime-scene-investigator.net/excavation.html Images: http://www.wadsworth.com/anthropology_d/special_features/forensics/forensics_index/index.html

Warm-Up: Video http://www.hulu.com/watch/474025#i0,p0,d0 As you watch the video, again write down key words/identifiers of victim’s age. During the second viewing, assess whether or not you think Dr. Brenan used accurate anthropological data to determine sex and age of victim

Questions: What is the easiest way to determine the gender (using the skeleton) of an individual, and why? What is the easiest way to tell (using the skeleton) whether a teenager is lying about her/his age, and why? Why can determining gender from a skull be difficult? Why should a forensic anthropologist use more than one bone (if possible) to determine the height of an individual? What other issue is important to question four, especially if there is only one bone from which to work?