Shovel-shaped teeth are a common trait among Native American and Asian populations, according to the U.S. National Library of Medicine. They are rare or absent in populations of European or African descent.
Three separate studies have reported the heritability of shovel-shaped teeth among Asian and Native American populations to be around 0.75, notes the U.S. National Library of Medicine. Ancient Asian populations, including the indigenous Jomon people, typically have a smaller tooth-shoveling grade than modern Asian populations, although the prevalence of tooth shoveling differs throughout Asia. The allele EDAR 1540C accounts for roughly one-fourth of the total heritability of the trait.