Avenio wrote:The sperm doesn't 'cease to exist' at fertilization, it merges with the egg. Maternal and paternal gene products (ie components of the sperm and egg's cytoplasm) are incredibly important in directing the development of the zygote.
Yes, but the sperm as an individual entity ceases to exist. Its constituent parts do not, but they merge with those of the egg to form a completely different entity: a zygote, which is a human being.
Look at the excerpts from embryology textbooks I posted earlier in this thread: they all agree that a human being is created at fertilization.



A 2 day old is completely dependant on her, and milk from her body. You still can't kill it.