[Spexxvet]

I voted at birth.
I don't know that anyone will ever be able to definitively determine biologically or mechanically when life begins. But philosophically, I think "IT", whatever "IT" is, becomes a human when the one carrying it decides it is. Fetuses are like turtles. If you name it and care for it, it is a pet, and part of your family. Or you can make soup out of it. In support of this, I would point out that I've never heard of a funeral for a miscarried fetus. It is NOT treated the same as a human child. Even anti-choice folks differentiate between an unborn entity and one which has been delivered.