Final answer:
The two major differences in leg bones between males and females are the thicker and heavier bones in males for supporting a greater body mass, and a broader and wider female pelvis with a greater subpubic angle, designed for childbirth.
Step-by-step explanation:
Major Differences in Leg Bones Between Males and Females
Leg bones in males and females exhibit distinct anatomical differences primarily due to adaptations for support, movement, and in females, reproductive functions such as childbirth. The first major difference is that the bones of the male pelvis, such as the femur, are generally thicker and heavier, which can be attributed to the need for supporting a male's heavier build and stronger muscles. A second notable difference is in the structure of the pelvis itself, where the female pelvis has a wider framework to facilitate childbirth. This includes a wider pelvic inlet with a round or oval shape, a broader subpubic angle greater than 80 degrees (compared to less than 70 degrees in males), and a shallow, more expansive lesser pelvic cavity. Additionally, the greater sciatic notch is generally broader in females.
The male pelvic bones are adapted for supporting a heavier body build and stronger muscles, whereas the broader, wider, and more shallow female pelvis is adapted to accommodate the passage of a newborn during childbirth. These differences are critical in forensic science and anthropology for sex determination of skeletal remains.