Final answer:
The pelvic girdle is the best area of the skeleton to determine the sex, noticeably different between males and females due to reproductive adaptations. The pelvic dimensions and angle differences are reliable indicators for sex estimation in adults.
Step-by-step explanation:
The best area of the skeleton to determine the sex is the pelvic girdle. The pelvic girdle attaches the lower limbs to the axial skeleton and is differentiated between males and females, primarily to accommodate reproductive functions. In females, the pelvis is wider, shallower, and the pubic angle is broader, contrasting with the male pelvis, which is generally narrower and more robust. Moreover, the pubic symphysis, the anterior joint where the pelvis comes together, is also a reliable indicator when determining sex in skeletal remains.
These differences in the pelvic area are notable and they adapt to reproductive fitness, with the female pelvis being lighter and designed to facilitate childbirth. The ischium and the angles between the pubic bones are different enough to be significant in sex estimation. This is supported by Figure 29.13 which illustrates these distinctions clearly.
In conclusion, while other parts of the appendicular skeleton, such as the cranium, can also provide clues to a skeleton's sex, the characteristics of the pelvis are considered the most reliable indicators in adult skeletons. Therefore, forensic anthropologists and other professionals often look to the pelvic girdle first when determining the sex of skeletal remains.