Final answer:
It is false that skeletons commonly show traits from just one racial group, as race is not a biologically valid concept and human traits are not confined to discrete categories.
Step-by-step explanation:
It is false that it is uncommon for a skeleton to exhibit characteristics of more than one racial group. Biological anthropology has shown that race as a biological category is not scientifically valid. Instead of discrete racial categories, human traits such as skin color, facial features, and blood type vary on a spectrum, and a mix of these traits can be seen across different populations.
For example, although skin color is often used to assign race, it is not a reliable indicator of distinct racial categories because it varies along a continuum. Furthermore, out of the thousands of genetic markers in human DNA, only a small portion actually relate to physical characteristics traditionally associated with race. Therefore, it is not uncommon for a skeleton, or any other biological indicator, to reflect characteristics that might be associated with multiple 'racial' categories.