Final answer:
Using a linear model to relate femur length to height, anthropologists can infer human growth and characteristics. Through a radiograph, this information can help estimate a child's age, especially when considering the general relationship between height and weight.
Step-by-step explanation:
Anthropologists employ a linear model that links femur length to human height to make various inferences about human growth, age, and biological characteristics. A child's femur can be analyzed through a radiograph to approximate their age because femur length correlates with growth stages. For instance, when examining the length-weight relationship, a graph illustrating this for American boys and girls from birth to 3 years shows that height and weight are related; taller children generally weigh more, and vice versa. Hence, by understanding these patterns, anthropologists can deduce useful information.
This reliance on bone structure, such as the femur, to approximate human characteristics is because larger bones in humans generally indicate a larger frame, which usually means more flesh and a higher weight. Yet, there are variations and exceptional cases which demonstrate that while the relationship is a solid general rule, it is not absolute. The evolution of bipedalism, which includes the angling of the femur at a valgus angle, also gives insights into how bipedal organisms evolved to handle weight distribution during locomotion.