The zygote: to be or not be a person

It is no longer possible to claim that the biological characteristics of the future adult are already determined at conception. After all, a zygote may develop into a hydatidiform mole rather than into a human being. The development of an individual human person is determined by genetically and non-genetically coded molecules within the embryo, together with the influence of the maternal environment. Consequently, it is an error to regard the zygote's chromosomal (and other) DNA as sufficient to determine the uniqueness of the future individual.