Biology provides a direct and objective knowledge about how and when life of a human being starts. When zygote appears, a human body is there in the middle of temporal processes of the transmission of life. Science clearly states that any human individual, while being an embryo, remains being the same individual in youth or old age. Body keeps changing in a continuous way from the very beginning till the moment of death; however, identity is maintained. Science provides also an indirect knowledge of the origin of each human being when showing that in the only life of each one dynamism of all biological processes and personal dynamism liberating the body from its enclosure within physiological automatism keep intertwined.