Okay, so I disappear and five years later someone finds my femur bone. However, I am built with very long legs and a very short torso.
So would the forensic anthropolgist (I’ve read the Bones mysteries and seen the TV shows) determine it’s the bone of a six foot tall woman? How would they know it’s 5’6" tall me?
It’s just an estimate based on the average length of femurs for people of known height. Based on the shape and density they can make adjustments for people of different builds, and knowing whether the bone came from a male or female they can make other adjustments, but it’s still just guess. Not a really wild guess either, they should be able to get the height within plus or minus 1 inch in the majority of cases.
It’s an estimate only. The human femur actually provides a fair amount of information. They can tell if you’re male or female depending on the angle of the femur head. They can tell what your musculature was like because of how thick the muscle attachments to the bone. Recently, they’ve figured out they can determine how much you weighed by how thick the femur is (makes sense, as the femur is weight bearing), but it can’t tell if that weight is muscle, fat, or even pregnancy. The epiphysis can tell them if you’ve reached adulthood, and wear and tear on the joint ends can allow them to estimate how old/how active you were. I don’t know if there are any racial markers available on the femur.
However, when it comes to your height, they’re working off a table of averages, almost like insurance agents. So, if you’re an outlier - very long legs for your body type, they’re going to come up with a height that’s actually above yours. If they only had your legbone to work from, that would be that. If they had other bones - pelvis, vertebrae, skull, they might be able to pick up enough information to see that your legs were long in proportion to the rest of you and adjust for that. The skull, of course, would give them a great deal more information about possible race and age.
It’s not really my field, so I’m picking a slightly tangential reference that was high in the Google results, but it cites earlier work that you can track down if you’d really like the straight dope…
So, from the abstract here
If you track down the previous investigations, I would hope it contains information on the variance of that ratio, which would tell you how reliable it is in the populations examined.
There is some racial information that can be estimated from the femur based on the torsion angle of the head in relation to the condyles and the curvature of the shaft…I think. Its been a few years since I’ve had physical anthropology, and my Bill Bass book is not currently available to me.
You remember correctly - both the shape and the amount and location of curvature in the femur are subject to racial variation and are used by forensic anthropologists to determine ancestry.
Though I expect that the femur-shape-based races don’t match up exactly to the more familiar pigmentation-based races.
I read a quote from a forensic anthropologist about racial identification where he said that when he was testifying about a decedent’s race he was essentially saying what it most likely said on the person’s driver’s license under “race,” but if you wanted to get together afterward for beers and discuss what race really is, the topic goes a lot deeper than that.