Humans Chin: Adaptation or relic?

The chin is a bony prominence located at the anterior aspect of the lower jaw called mandibular symphyseal. The salient features of the symphyseal region are a raised central keel that flows into a distended lower margin, a low-lying triangular mental tuberosity at the confluence of the keel and the inferior margin, and mental fossae that lie on either side of the keel and above the distended lower margin. The shape of the chin is a significant characteristic that distinguishes humans from other primates. The shape of the human chin is established during fetal development and remains unchanged into adulthood. Neanderthals did not have this distinctive chin shape, and their mandibles were broad and arcuate. Some fossils that are typically classified as Homo sapiens display a human-like chin shape, while others have no distinctive features.