Final answer:
The closure of the sutures of the skull can be used to estimate an individual's age, as the sutures ossify and fuse at various stages of life. This process is known as synostosis and is studied using both traditional methods and newer techniques like transition analysis to determine age more accurately.
Step-by-step explanation:
From studying the closure of the sutures of the skull, the age of an individual can be estimated. Other characteristics such as sex, height, or racial ancestry are not directly assessable through suture closure. Sutures are fibrous joints that connect the bones of the skull, and over time they ossify, which is a process known as synostosis.
During infancy and childhood, sutures are necessary for the brain to grow and for the skull bones to expand. As a person ages, these sutures gradually ossify and fuse together, causing the suture lines to become less distinct. This ossification process occurs at different times throughout a person's life, providing a timeline that can be correlated with age. For example, early suture closure in life can lead to conditions like craniosynostosis, whereas later in life, the ossification of sutures is more associated with natural aging.
By using reference samples known as traditional methods, researchers assign a skeleton to one of several stages based on suture morphology and estimate age intervals. However, these traditional methods may inherit biases, such as underestimating the age of older adults due to a reference sample predominately composed of younger individuals, or failing to discern between older age ranges. Newer methods, such as transition analysis, attempt to more accurately estimate age by using different skeletal-age markers, including suture closure.