Human life spans may be limited to a maximum of about ... deficient methods and pretty graphics to attempt to prove their gut feelings. "[This study] adds nothing to scientific knowledge about ...

To the Editor: Re “When Does Life Start? A Post-Roe Conundrum” (front page, Jan. 2): When during gestation does an embryo become a human? This question has baffled philosophers and theologians ...

Jan Vijg a professor of genetics at the Albert Einstein College of Medicine in New York City, who has also researched the limits of human life span, agreed, saying that Dr. Olshansky’s study was ...