Complex sentence: Race involves the categorization of humans into populations or ancestral groups on the basis of various sets of heritable characteristics, usually visual traits such as skin color, facial features and hair texture.
Split into simpler sentences: Race involves the categorization of humans into populations or ancestral groups on the basis of various sets of heritable characteristics. The physical features commonly seen as indicating race are salient visual traits such as skin color, cranial or facial features and hair texture.