There is also a voting process which is fertilization. Only about one in a billion sperm will be elected to produce this new set of information. Once the head of the sperm has gone inside the zona pellucida, which is a kind of plastic bag which protects the private life of the early human being, there comes a moment when a new human constitution is voted for and enacted. Roe v. Wade said that because nobody can really know at what moment human life begins, we are free to decide such and such. Since then 17 years have elapsed, and science has made vertiginous progress.
Life has a very, very long story.
It has been transmitted for millennia inside the human race. But each of us has a very precise starting moment, which is the time at which the whole necessary and sufficient genetic information is gathered inside one cell, the fertilized egg, and this moment is the moment of fertilization. There is not the slightest doubt about that. It's a long molecule on which, under a specific code, all the qualities of the future person are defined. To help you understand the miniaturization of these tablets of the law of life, this meter-long molecule is coiled so tightly that it fits easily on the point of a needle.