When does life begin?

(Image of a baby 8 weeks old)

Or to put it in a way that makes people (B.O.) squirm: When do human rights begin? Here are a few people who don't think it's above their pay grade to talk about it. From First Things Blog (Frist things is a Christian/Catholic culture and philosophy journal):

When Does Human Life Begin?
Posted by Keith Pavlischek on August 18, 2008, 3:48 PM

Dr. Hymie Gordon (Mayo Clinic): “By all criteria of modern molecular biology, life is present from the moment of conception.”

Dr. Micheline Matthews-Roth (Harvard University Medical School): “It is scientifically correct to say that an individual human life begins at conception.”

Dr. Alfred Bongioanni (University of Pennsylvania): “I have learned from my earliest medical education that human life begins at the time of conception.”

Dr. Jerome LeJeune, “the Father of Modern Genetics” (University of Descartes, Paris): “To accept the fact that after fertilization has taken place a new human has come into being is no longer a matter of taste or opinion . . . it is plain experimental evidence.”

Rick Warren: At what point does a baby get human rights in your view?
Sen. Barack Obama: Well, I think that whether you are looking at it from a theological perspective or a scientific perspective, answering that question with specificity, you know, is above my pay grade.