The degree of separation of the earlobe from the head is a polygenic trait (depends on several genes) and is not an "all or nothing" genetic trait, but rather there is a continuous distribution and there are degrees of earlobe attachment.tically responds to an "all or nothing", but rather there is a continuous distribution and there are degrees of earlobe attachment. Furthermore, it is a trait that is highly determined by the geographic ancestry of the individual.

Based on a genome-wide association study (GWAS) involving 75,000 individuals of different geographic ancestries, 3 markers associated with the likelihood of having the earlobe more or less separated from the rest of the head have been identified.

The identified markers are found in genes such as the EDAR gene, which produces the ectodysplasin A receptor protein, which plays an important role in the development of ectodermal tissues such as skin; the ITGA8 gene, related to wound healing and organogenesis; and the ADAMTS9-AS2 gene, used as a possible marker in the development of some types of cancers.

The study of this trait is important because on certain occasions this phenotypic trait may be associated with certain developmental disorders and malformations (e.g., defects in the jaw musculature and defects in the morphology of the jaw).The study of this trait is important because the genes that are associated with the type of earlobe a person has are also involved in development.

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