SHOVELING into the North Italian Bronze Age with an integrative approach to unearth the evolutionary origins of a non-metric dental trait - SHOVELING

Shovel-shaped incisors are common among extant Asians (65%-97.5%) and Native Americans (99.5%), but rare in other human groups, in particular at their higher scores (5-7, with 7 indicating extremely shoveled teeth). Scholars have proposed diverse evolutionary explanations for the origin and spread of this dental non-metric trait. Recently, a mutation has been identified in a pleiotropic gene, EDAR, which is behind shoveling teeth and other phenotypic traits. The mutation might have arisen in China or Beringia about 20000 years ago, and have become established possibly because of positive selective pressures, before spreading to the Americas. Although tooth shoveling was not uncommon in prehistoric Italy, the presence of this trait with high scores in individuals of Bronze Age populations (1859-950 BCE) from Northern Italy - a key place for population movements - needs to be better clarified. Several hypotheses may be proposed: (i) earlier or coeval migrations from Asia; (ii) ancestral inheritance from a hominin; (iii) local selection due to diverse possible agents. To test which of the proposed hypotheses might explain the presence of shovel-shaped incisors in Italian protohistoric individuals, we propose an integrative approach which includes anthropological investigation, ancient DNA and stable isotope analyses, along with genetic examination of modern populations from different regions. The proposed research will elucidate population dynamics or adaptation of Bronze Age people in Northern Italy, contributing to shed light on our ancestry. Moreover, and even more significantly, it will highlight from an ancient perspective the evolutionary aspects behind the development of a pleiotropic gene, its interplay with environment and cultural behaviors, and possibly its interaction with other genetic sites.