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Forensic Science. Unit 4B Day 7. Forensic File. What is the correct order for the arrival of the following insects at a body from first to last? Ants Beetles Flies Spiders Wasps. Anthropology Evidence.
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Forensic Science Unit 4B Day 7
Forensic File • What is the correct order for the arrival of the following insects at a body from first to last? • Ants • Beetles • Flies • Spiders • Wasps
Anthropology Evidence • You have THREE class periods to finish these assignments!!!! This does NOT include this Thursday. • DUE TODAY: • All insect evidence assignments • Diagramming injuries & Using anatomical terms assignments
What is osteology? • Study of bone structure and growth of bone tissue
How can bone Sutures be used to determine age? • Three major cranial sutures appear as distinct lines in youth and gradually close from inside out • Basilar sutures close in females as young as 14 and males as young as 16. If suture is open, the individual is generally considered 18 or younger
Age continued • Long bones of legs & arms: growth plate remains open as they are growing, then close up when growth stops; Bones complete their growth around age 25 • Pelvis: symphysis (band of cartilage attaching pelvis to spinal column) has zigzag shape , but straightens as age; stopping around age 50 • Ribs: sternal ends of ribs are smooth and rounded in youth, but become pitted and sharp as we age • Bone density: bones lose calcium as we age
How can bones be used to determine gender? • Pelvis of female is wider • Males have a narrow subpubic angle (A) and a narrow pubic bone body (B)
male female Sub pubic Angle
Gender differences cont. • Ribcage and shoulders of males are generally wider and larger than females • In addition, about one person in twenty has an extra rib • This is more common in males than in females
Gender differences cont. • Although occurring less consistently, males typically have index fingers that are shorter than their ring finger • In females the index finger is typically longer than the ring finger. Is this a male or female hand according to the above rule?
How can bones be used to determine height? • Height of a person can be calculated by using the length of certain bones (femur, tibia, humerus, & radius) • To the right are average measurements for both males and females • More specific charts are available if you know the race of the individual • All measurements are in centimeters
How can race be determined from the bones? • Race is difficult to determine from most skeletal remains • An experienced forensic anthropologist can generally place skulls into one of three groups: • Caucasian • Negroid • Mongoloid
What differences do you notice between these three skulls? Could you tell each race? Racial identification is impossible if someone is of mixed race