Final answer:
In a pedigree, a shaded circle would illustrate a person with attached earlobes, which are an autosomal recessive trait represented by 'ee'.
Step-by-step explanation:
In a pedigree tracking earlobe attachment, shaded symbols are used to show individuals who express a recessive trait. In this case, attached earlobes are the recessive trait which is represented by the genotype 'ee'. Therefore, a shaded circle in the pedigree will illustrate a person with attached earlobes. A person with free earlobes, which is the dominant trait, would not be shaded in a pedigree. It is impossible for a person to have both attached and free earlobes, as earlobe type is determined by a single gene, and the free-hanging earlobe trait (E) is dominant over the attached earlobe trait (e). A pedigree symbol for a person with an unknown earlobe type would be unshaded and typically marked with a question mark inside the symbol.