Establishing Identities: Forensic Anthropology
Sometimes all that's left of a body by the time it's discovered is a skeleton or pieces of bone. In a situation like this a forensic anthropologist may be called in to help identify the victim.
Brenda Clark is a forensic anthropologist in Victoria, BC. In this lesson you will learn how she can help determine things such as the age, sex, height, and lifestyle of a victim from the skeletal remains. Much of this information is in text, but there are several very interesting and educational video clips as well. Be sure to check these out.
Brenda Clark is a forensic anthropologist in Victoria, BC. In this lesson you will learn how she can help determine things such as the age, sex, height, and lifestyle of a victim from the skeletal remains. Much of this information is in text, but there are several very interesting and educational video clips as well. Be sure to check these out.
- Sometimes all that's left of a body by the time it's discovered is a skeleton or pieces of bone.
- In a situation like this a forensic anthropologist may be called in to help identify the victim.
Estimating Age: Bone Fusion
- One way FAs can estimate the age of a body is to look for evidence of bone fusion.
- When you're born, many of your bones are in separate pieces, like in Image A.
- As you get older, these pieces fuse together into a single bone, like in Image B.
- As you can see in Image C, each of your bones fuses at a different age.
- Can estimate the age of the victim.
- If the elbow is fused, for example, the victim is likely at least 14 years old.
- However, if the wrist isn't fused, the victim is likely less than 19.
- Combining these two pieces of information, we can estimate the victim's age more precisely - in this case somewhere between 14 - 18 years of age.
- Bone fusion is a useful indicator of age for children, teenagers, and young adults.
- Once all of your bones are fused, however (about 28 years of age), it's much more difficult to estimate age.
Estimating Age: Teeth
- Another good indicator of age in young people is teeth.
- Your first teeth (baby or deciduous teeth) start to come in some time between birth and one year, and are all in place by about age two.
- When you're about six, your first permanent teeth (adult teeth) then appear.
- By the time you're about twelve, all your permanent teeth (except for your wisdom teeth or third molars) are in place.
- Knowing which teeth are in place, and how many of them, FAs can help approximate the age of a young person.
Estimating Age: Bone Density
- As people age their bones become less dense because mineral deposits break down faster than they are built up.
- Keep in mind, though, that bone density is extremely variable.
- Two people of a given age can have vastly different densities, based on things like overall health and diet.
Estimating Age: Shape of Rib Bones
- FAs can also estimate a victim's age by looking at the rib bones.
- When we are young, the ends of our rib bones that attach to the sternum are very smooth.
- As we get older, these ends become jagged.
Determining Gender: The Pelvis
- As you can see in Image D, females have much wider pelvises than males.
- This is especially noticeable in the ilium (the large flared part of the pelvis) and the arch or gap between the left and right pubic bones.
- Can you think why females have wider pelvises?
- If you said so they can deliver a child, you're right!
- Using the pelvis to determine sex is 90 - 95% accurate.
Determining Gender: The Skull
- In general, the male skull is larger and squarer than the female skull, with more prominent features.
- Muscle attachments are also more pronounced on male skulls as well.
- And you can't really see it from the drawing, but the male skull also has more bony protuberances (bumps) than the female skull.
Estimating Height
- FAs can also estimate a victim's height by measuring the length of long bones in the body.
- The best bone for this is the femur, or thigh bone.
- After measuring the length of this bone, FAs applies a mathematical formula to estimate overall height.
- The human body is approximately 8 times longer than the head (skull) alone.
- So if you measured the distance form the top of a skull to the bottom of the chin and it was 20 cm, you would predict the height of the person to be 160 cm (20 cm X 8 = 160 cm).
- This is only an approximation - there is no way to tell for sure how tall the person was.
Predicting Lifestyle
- FAs can also tell a lot about a person's lifestyle by looking at his or her bones.
- FAs know that certain jobs or activities will result in more wear and tear on some bones than others.
- In addition, old fractures that have healed can tell her something about the life of a victim.
- FAs can even tell if a person is right or left handed based on the size of the limb bones on each side of the body.
- Your arm and leg bones, for instance, will be larger on your dominant side.
Important Terminology
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