There is a definitive answer – at conception. Because there is no other benchmark that is not arbitrary, there is no other benchmark that makes more sense.
What is a fertilized egg? The very question screams out the answer. The change before and after fertilization is greater than any other developmental change, from two sex cells that would otherwise soon die to a new life with its own unique genome. Fertilization is the obvious beginning of human life. This is not opinion, this is objective fact.
A fertilized egg is a living, individual human life. There is no reason, other than the convenience of adults, to claim otherwise.





