"Even if the justices don’t overturn Roe, they could effectively end the precedent by erasing its viability standard, which permits abortion up until a fetus can survive outside of the womb. If the court shifts this standard on the basis of arguments about when a fetus becomes a person, the research filed to the justices might not matter. Because this question is not something that science clearly defines, Toti says, courts generally haven’t debated it. But that could change."