Welcome to Science Sundays! Today I thought I'd launch into a topic I spent a while going over with my students this past week: how to tell the sex of an individual from the skeleton. More specifically I thought I'd hit the high points of the pelvis, because really there are textbooks worth of information on this subject :)
This is the view from the back (butt side). |
(Confusing you yet? Here's an example: males are generally taller than females, so a tall skeleton would be thought to be more likely male than female, but of course there are tall females too, so it could also be a female. Same thing applies here--the range of variation may be leaning toward one sex, but sometimes the variability falls into the grey area in the middle.)
highlighted area is the notch. |
The 1 is more female, the 5 more male. |
Prearicular sulcus region. |
>There are three traits that are found on the pubis bone of the pelvis (each half of the pelvis is actually made up if three, fused bones [in adulthood] that are known at the ilium, ischium, and pubis). The pubic bone is the one that comes together in the front, belly-side of the body in the pubic area (hence the name!). These traits are kind of hard to describe without actually looking at a bone but if you're curious, these are things that can also be analyzed:
Ventral Arc: A is female, B is male. |
Subpubic concavity: C is female, D is male. |
Ischiopubic ramus ridge: B is female, F is male. |
-Subpubic Concavity.
-Ischiopubic Ramus Ridge.
Yay! So, that's the best way to tell what sex an individual was in life. Do keep in mind this doesn't mean their gender :) (I always kind of wonder if this gets any more particularly confusing in areas with large LBQT communities where the sex an individual is born with can be different from their gender--the underlying bones don't change without obvious modification...something random I think about, which is probably an insight into my mind that you didn't want to know!)
Questions?
Interesting final point. Once we're dead thoughts nobody's ever going to look at a transgender pelvis and guess the psychological sex of the person. That is a cool premise, Meradeth!
ReplyDeleteThanks! I think so :) Something I always bring up in class too--I want my students to remember it because I believe it's important to keep in mind!
DeleteDelete "thoughts" in the 2nd sentence, that makes no sense.
ReplyDeleteFascinating post!
ReplyDeleteI always wondered how the pathologist could tell the difference. Thanks Meradeth :)
ReplyDelete