Figure 2. Heritability maps of the human face.

Each heritability map consists of 4,096 landmark heritability estimates. Facial areas with high heritability across all four maps were the mental region, philtrum, nasal tip, nasion, inner eye corners, nasolabial folds and frontal process of maxilla. Mean Curvature Heritability Map: In addition to aforementioned areas, we observed genetic association along the lower parts of the eyes (zygomatic bones), the sides of mouth/chin complex (mental foramen), the complete upper lip region and the frontal eminences. Gaussian Curvature Heritability Map: Compared to the previous map, zygomatic bones were not clearly distinguished and only the philtrum had high heritability in the upper lip region. A moderate genetic effect was observed around the whole nasion area. Curvedness Heritability Map: The map included clear heritable lines in the upper and lower circumference of the facial surface. A further unique feature observed here was a flat heritable area around the ramus of the mandible. Shape Index Heritability Map: Zygomatic lines were clearly visible in this map, along with the upper lip and the frontal eminences. The map highlighted primarily the mostly concave regions of transition between the lip and ala of the nose, the frontal process of maxilla and the lower more protruding parts of the nasal bones.