Diaphyseal length in subadults is characterized by what relationship to age and variation?

• A. It has a strong relationship with age and little sex or population variation
• B. It has a weak relationship with age and high variation by sex
• C. It shows no relation to age
• D. It is useful only in adults

Answer: (A)

Growing long bones lengthen in a predictable way as a child ages, so diaphyseal length during subadolescence tracks chronological age very well. Because this growth occurs before puberty, differences due to sex are small and population-based variation is limited, making age the dominant signal. In subadults, the active growth plates drive length increases, whereas sex and population effects become more noticeable only later, after puberty. So the diaphyseal length in subadults provides a strong age relationship with relatively little variation from sex or population.