the only recognized extant obligately bipedal primates, meaning the body shape requires to only use two legs, major evolutionary developments had to occur in order to alter to the shape of the female pelvis. Human males evolved narrower hips optimized for locomotion, whereas female hips evolved to be a wider optimization because of childbirthing needs. Human pelvises have no distinguishing skeletal markers for sex before puberty, meanwhile, with maturation, hormones and obstetrical demands alter the shape of the pelvis in females. Overall, through evolution of the species, a number of structures in the body have changed size, proportion, or location in order to accommodate bipedal locomotion and allow a person to stand upright and face forward. To help support the upper body, a number of structural changes were made to the pelvis. The ilial pelvic bone shifted forward and broadened, while the ischial pelvic bone shrank, narrowing the pelvic canal. These changes were occurring at the same time as humans were developing larger craniums. Male versus female Examination of the pelvis is the most useful method for identifying biological sex through the skeleton. Distinguishing features between the human male and female pelvis stem from the selective pressures of childbearing and birth. Females must be able to carry out the process of childbirth but also be able to move bipedally. The human female pelvis has evolved to be as wide as possible while still being able to allow bipedal locomotion. The compromise between these two necessary functions of the female pelvis can be especially seen through the comparative skeletal anatomy between males and females. The human pelvis is made up of three sections: the hip bones (ilium, ischium and pubis), the sacrum, and the coccyx. How these three segments articulate and what their dimensions are is key for differentiation between males and females. Females acquired the characteristic of the overall pelvic bone being thinner and denser than the pelvic bones of males. The female pelvis has also evolved to be much wider and allow for greater room in order to safely deliver a child. After sexual maturation, it can be observed that the pubic arch in females is generally an obtuse angle (between 90 and 100 degrees) while males tend to have more of an acute angle (approximately 70 degrees). This difference in angles can be attributed to the fact that the overall pelvis for a female is preferred to be