What are the benefits and limitations of using ethnic origins as a factor in the analysis of bones?

The benefit of using ethnic origins as a factor in the analysis of bones is that you can tell the ethnicity of the person by looking at the skull. White people and black people have a different shaped nose, for example. There is a limitation because of different ethnicities mixing together. For example, a black male, and a white female have a baby. The baby will be part black and part white. It would be harder to identify the baby's ethnic origins.