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Chapter 13 Forensic Anthropology: Dead Men do Tell Tales Anthropology and Crime Kathy Reichs- Bones 1 Historical Development 1. In the 1800s, scientists began studying skulls. This laid the framework for today’s knowledge. 2. In 1932 the FBI opened the first crime lab. 3. The Smithsonian Institution became its working partner in the identification of human remains. 4. Soldiers killed in World War II were identified using anthropologic techniques. 2 Forensic Science: Fundamentals & Investigations, Chapter 13 Development of Bone Bones originate from cells called osteoblasts. They migrate to the center of cartilage production and deposit minerals. Throughout life, bones are being broken down, deposited, and replaced. Osteoclasts, the 2nd type of bone cell, among other tasks, remove cellular wastes. 3 Forensic Science: Fundamentals & Investigations, Chapter 13 How Bones Connect Bones are held together by: a. cartilage—wraps the ends of bones and keeps them from scraping one another. b. ligaments—bands that connect two or more bones together. c. tendons—connect muscle to bone. 4 Forensic Science: Fundamentals & Investigations, Chapter 13 As long as cartilage is present bones can still grow – – 5 Females- grow till 18 Males – grow till 20-21 18-30 years old- bone loss= bone mineral deposit After 30 – bone loss exceeds deposits (bones shrink) , can lessen with exercise Forensic Science: Fundamentals & Investigations, Chapter 13 What Bones Can Tell Us Osteobiography tells much about a person through the study of the skeleton. The bones of a right-handed person, for example, would be slightly larger than the bones of the left arm. Forensic scientists realize that bones contain a record of the physical life. Analyzing bones can reveal clues to such things as gender, age, height, and health. 6 Forensic Science: Fundamentals & Investigations, Chapter 13 Gender - Skull Female skull is rounder and smaller than 7 males Female forehead is longer vertically and jaw is smaller Male jaw is square with an angle of 90 degrees Occipital protuberance (bony knob on base of skull)on males is larger Forensic Science: Fundamentals & Investigations, Chapter 13 Gender - Pelvis The surface of a woman’s pelvis can be 8 scarred after childbirth The sub pubic angle of the female pelvis is greater than 90o, ;lighter and smoother, the male’s, less Female tailbone (coccyx) is more flexible Woman’s pelvic girdle is wider Forensic Science: Fundamentals & Investigations, Chapter 13 Pictures 9 http://anthropology.si.edu/writteninbone/comi c/activity/pdf/skeleton_male_or_female.pdf Forensic Science: Fundamentals & Investigations, Chapter 13 Age 10 By about age 30, the suture at the back of the skull will have closed. By about age 32, the suture running across the top of the skull, back to front, will have closed. By about age 50, the suture running side to side over the top of the skull, near the front, will have closed. Forensic Science: Fundamentals & Investigations, Chapter 13 11 Forensic Science: Fundamentals & Investigations, Chapter 13 Age During life, many of the 450 bones a person has at birth grow together, finally forming 206 bones. As the cartilage between them is replaced, an epiphysis line is visible. When the cartilage is fully replaced, the line is no longer visible. Ends of sternal rib bones are rounded in young adults, jagged and cup shaped w/ age 12 Forensic Science: Fundamentals & Investigations, Chapter 13 Age- Teeth 13 Look for eruption of baby teeth or permanent teeth (occurs at regular intervals- very accurate Loss of permanent teeth associated with old age Teeth wear occurs w/ age and more dentine (yellowing) is exposed with loss of outer white tooth enamel Forensic Science: Fundamentals & Investigations, Chapter 13 14 p,. 15-16 Teeth Eruption (can look through other pages for female/male/ age charts) Forensic Science: Fundamentals & Investigations, Chapter 13 Height An estimate of height can also be made by looking at arm and leg bones. Often, the approximate height of a person can be calculated from one of the long bones even if just one of those is found. (formulas on page 371) Gender and race will need to be taken into consideration in making the estimate. 15 Forensic Science: Fundamentals & Investigations, Chapter 13 Race 16 Classify into three categories: Caucasoid (includes European, Italian, Arab, Indian), Negroid (African, Jamaican) , Mongoloid (Asian, American Indian, Alaskan, Hawaiian, South American) Forensic Science: Fundamentals & Investigations, Chapter 13 General Race Characteristics 17 Forensic Science: Fundamentals & Investigations, Chapter 13 Race 18 In the absence of DNA, can you really determine race from a jawbone? Probably not. If you place an Asian jawbone on a table, the bottom of it will likely maintain contact with the tabletop all the way around. African and Caucasian mandibles, in contrast, tend to undulate, or rise and fall along the lower border. Forensic Science: Fundamentals & Investigations, Chapter 13 Race The gonia—that's the area beneath your ears where the jawbone turns upward—generally curve more sharply in an Asian jaw. People of African descent often have slightly curled surfaces on the rear edges of their jaws, whereas European jaws are more likely to have a flatter edge. Racial classification is an inexact science, if that's even the right word for it. Forensic anthropologists never make definitive ancestry pronouncements. They say a bone is "consistent with" European ancestry or "likely" of Asian ancestry. Forensic Science: Fundamentals & Investigations, Chapter 13 19 Article: Scientists disagree between race and bones 20 http://abcnews.go.com/Technology/t/story?id =98485&ref=https%3A%2F%2Fwww.google. com%2F Forensic Science: Fundamentals & Investigations, Chapter 13 Facial Reconstruction (how its made-facial) http://www.youtube.com/watch?feature=endscreen&v=6G0LvImAGAg&NR=1 *A face is formed by the skull with the muscles and 21 tissues on top of the skull. *Theoretically, nonetheless, a face can be rebuilt from just skeletal remains. *Facial markers are positioned at critical locations on a skull, and clay is contoured to follow the height of the markers. Today, computer programs perform a similar function. These computer programs also can age missing persons and criminals. Forensic Science: Fundamentals & Investigations, Chapter 13 DNA Evidence *Bone contains little nuclear DNA. *But it does contain mitochondrial DNA. *This has DNA that is inherited only from the mother. Long after nuclear DNA has been lost through tissue degeneration, mitochondrial DNA can be obtained from bone. Results can be compared with living relatives on the mother’s side of the family to identify skeletal remains. 22 Forensic Science: Fundamentals & Investigations, Chapter 13 Skeletal Trauma Analysis *Forensic anthropologists often determine if damage to bones occurred before or after death. Definite distinctions exist between patterns on bones made by weapons and the patterns created by the environment after death. Sharp-force trauma, blunt-force trauma, gunshot wounds, and knife wounds all have distinctive patterns. 23 Forensic Science: Fundamentals & Investigations, Chapter 13 . . . . . . . . . . Summary . . . . . . . . Bones are live and carry on all life functions. The condition of bones can tell investigators about a person’s health and nutrition during life. Male and female skeletons differ in many ways. The age of a person at death can be estimated by analysis of a number of bones. 24 Forensic Science: Fundamentals & Investigations, Chapter 13 . . . . . . . . . . . . . . . . . Summary A person’s height can be estimated by the length of long bones. Facial reconstruction is possible to some extent. Mitochondrial DNA can be extracted to help identify skeletal remains. Skeletal trauma analysis examines bones for evidence of damage. 25 Forensic Science: Fundamentals & Investigations, Chapter 13 26 CSI- Murfreesboro Bone –gunshot (bill bass) Smithsonian Bone Detective (56 min lectureanthropologist)-start 15 min in Forensic Science: Fundamentals & Investigations, Chapter 13 27 Forensic Science: Fundamentals & Investigations, Chapter 13 Bone Height – Caucasion: – Male: 3.76 x length ulna (cm) + 75.55 (+ or – 4.72) – Female: 4.27 x length ulna (cm) + 57.76 (+ or – 4.30) 28 Forensic Science: Fundamentals & Investigations, Chapter 13 Height Lab Purpose Part 1: Ulna bone length, predicted height with formula, actual height converted to cm and % error Part 2: – – 29 Data table 1- convert actual height to cm, Data table 2 – measure ulna bone, using formula predict height, do % error, Graph (of actual height (data table 1) vs ulna bone length (data table 2) Questions (including your predicted height using graph and % error) Forensic Science: Fundamentals & Investigations, Chapter 13 30 Forensic Science: Fundamentals & Investigations, Chapter 13 31 Vitruvian man video- BBC (15 min) Forensic Science: Fundamentals & Investigations, Chapter 13 32 Forensic Science: Fundamentals & Investigations, Chapter 13 33 Forensic Science: Fundamentals & Investigations, Chapter 13 34 Forensic Science: Fundamentals & Investigations, Chapter 13