“PGD has also been used for other controversial purposes, such as the birth if so-called savior siblings, destined from the moment of implantation not only to live their own lives, but also to serve as organ or cell donors for a sibling.” ScienceGene EditingControversial Purposes Book:A Crack in Creation: Gene Editing and the Unthinkable Power to Control Evolution Source: A Crack in Creation: Gene Editing and the Unthinkable Power to Control Evolution