The only difference between a male and female human skeleton model is that the female has a more rounded pelvis, but in fact there are many subtle differences between male and female skeletons.
As anyone who’s taken a basic biology class knows, males and females have different chromosomes that determine gender. The entire chromosomal profile of an organism is included in every individual cell, so it is possible to identify gender by examining the DNA of even a single cell. The different chromosomes in males and females result in several differences in development, most notably the hormones present in the body. Females produce a greater amount of estrogen (the “female hormone”), which in turn affects their bone development in several key ways. Males, on the other hand, produce a greater amount of testosterone (the “male hormone”), which likewise affects the development of male bones.
First of all, males’ and females’ bones develop at different rates. We all know the adage that girls mature faster than boys, and while this old axiom is meant to refer to emotional maturity, it is also true of the human skeleton. All humans are born with a portion of cartilage in their bones, which starts out flexible and becomes more firm over time, resulting in the hard texture we all associate with bones.
The bones in a female body complete their development sooner than those in the male body. Female bones complete their development around age 18, while men’s bones continue to mature until around age 21. This is part of the explanation behind the difference in the average size of male and female bones—as the male bones continue to grow and develop longer, they also become larger (on average) and have more pronounced corners. Thus, the relative size of several key features can be used to identify a male vs. female skeleton. In males, the jaw bone is generally larger and more pronounced, and the brow is taller. Male skeletons also generally have longer, thicker bones in the arms, legs and fingers.
In females, a large part of the course of development from child to adult involves the body preparing itself for childbirth. This major difference between men and women is the cause of the biggest hallmark feature of a female vs. male skeleton, the pelvis. In females, the pelvic bones are shorter and more rounded, and the surrounding bones (tailbone, remaining hip bones, etc.) are designed to be more flexible to accommodate gestation and child delivery. In a female skeleton, the space between the two major pelvic bones must be able to accommodate a baby’s head and shoulders during childbirth.
While there are several differences between male and female skeletons on average, all the differences are relative so it is nearly impossible to identify gender from skeletal measurements alone. The majority of people will fall into the average ranges of bone size for their gender, but with so many people in the world (not to mention subtle differences between different ethnic groups due to geographical factors) there are bound to be a lot of statistical outliers.
Even the key discerning feature, the pelvis, can vary between individuals. Some women’s pelvic girdles are too narrow to accommodate childbirth and they must deliver a child through a Caesarian section. Some men are short, with rounded jaws and small frames. Even noting these subtle differences between the male and female skeletons, it is important to remember that male and female skeletons are much more alike than different. The most disparate-looking individuals still have more commonalities than differences, physically speaking.
Check out our review site with detailed comparisons of the best human skeleton models. All but one of the models on our lineup are male, but as mentioned above, the only difference between the genders in a skeleton model is the pelvic structure, so regardless of gender a human skeleton model can be useful for learning the details of the human body’s infrastructure.