Mental gymnastics and not very convincing ones at that. A zygote has a unique DNA structure that has a natural drive to develop, including to develop the gametes. The gamete does not have a unique DNA structure that has a natural drive to develop.
An infant is not a seperation from a zygote, nor is an adult, they are stages of development from the same zygote. To equate the gamete as a period of development after the adult stage is to claim that an adult develops into a skin cell, or a white blood cell. The adult human does not develop into the adult gamete, is produces the gamete.
Zygote (human) -> Infant (human) -> Adult (human) -> White Blood cell (human)
Is that really how you view the circle of life?
Sorry, again a horrid logical argument.
By the way, you still haven't answered my very simple questions.