Human Life Begins at Fertilization

"Noted embryologists O'Rahilly and Muller place the beginning of the life of a new organism at fertilization"-Once again, I have made no claim that states that an organism at a cellular level is not alive. In fact, my opponent seems to have completely ignored my statement in the first round. "Drawing a mistaken conclusion from a 9th grade textbook isn't going to cut it."-Note that my opponent offers no rebuttal to my claim, he simply dismisses it. He fails to demonstrate how my conclusion is "mistaken." Along with ignoring my distinction between human beings and living cells, it seems my opponent does not take this debate seriously. He is simply waiting for his turn to speak.I will now address the counter-claims that my opponent offers to support his initial claim. First claim: Human beings are characterized by a "unique DNA fingerprint." -This is insufficient in characterizing human beings. For example, the Muntjac(1) is a deer with 46 chromosomes—one of several animals with 46 chromosomes. Of course, my opponent would not consider the barking deer a human. Therefore, this premise fails to support his conclusion. Second claim:"The only thing this entity needs is a proper environment and adequate nutrition to develop herself as an individual member of the species. It is an organism whose development is being driven from within. It is developing itself to the next stage of the organism according to the nature of the organism."-Pro is simply stating that zygotes bear the potential to become humans, one day. He is being intentionally opaque by using phrases such as "driven from within" and "it is developing itself" in an attempt to speculate on what is responsible for the zygote's development. This does not express how human life begins at fertilization. If he is referring to the zygote's nature of utilizing the nutrients imbibed from its host, then he is not describing the nature of an independent human being. He is describing a parasite(2).Please note that my opponent has failed to refute my arguments made in the first round. Pro asks me:"At what point in development do you believe a zygote/embryo/fetus becomes a member of the human species?" "What was it before?" "But I'm going to need some actual evidence that shows all the embryologists and pro-abortion-choice philosophers are wrong."-My opponent is now attempting to offer the burden of proof to me. However, I have not made the claim that is in dispute; therefore, I do not have the burden of proof. I respectfully decline his offer as it is irrelevant.Also note that my opponent's claims have moved from the subject of the beginning of human life, to claims defending a pro-life stance on abortion. He is back-peddling into a more generalized and disputed subject. Now, Pro is soliciting the claims of embryologists and philosophers to his side without explaining how any of them support his conclusion. However, I will entertain the direction in which he is moving.My opponent is hinting at the "potentiality" argument. Meaning, a fetus has the "potential" to be a human being. Therefore, it should be shown respect as potential life. Do we show the same respect to the potential life of chicken eggs, or fish eggs? I doubt my opponent has devoted any time defending the right-to-life of spider eggs.So, should we show respect to embryos, simply because they could be like us one day?Is this a sufficient premise on which to base one's morality?Please note that I have refuted Pro's counter claims, while my previous claims in the first round still have not been rebuked.References:1. http://en.wikipedia.org...2. http://www.google.com...