The phrase "of common descent" implies a shared ancestry or origin among a group of individuals. Synonyms for this phrase might include "related by blood," "descendants of a common ancestor," "having a shared lineage," or "united by a common heritage." Other options might include "having common ancestry," "of the same family tree," or simply "belonging to the same group of people." Whatever the phrasing, these synonyms all communicate the idea of a shared history or ancestry among a group of individuals, highlighting the ways in which our past can shape and connect us in the present.