There has been lot of confusion of logic on this thread, let me see if I can clarify it. The prolife argument goes as follows:
Human beings have heartbeat.
Fetus has a heartbeat.
Therefore, fetus is a human being.
For heartbeat, substitute, DNA, formation of limbs, brainwave etc. This is faulty logic. These things characterize a human being, are manifestations of humanity, but they do not define humanity. Let me explain with an example.
How do we know that somebody is a millionaire? If he drives a Ferrari, does that mean that he is a millionaire? If he owns a yacht, or has a trophy wife, does that mean that he is a millionaire?
It does not. Ferrari, yacht, trophy wife, these are all manifestations of wealth, but they do not define wealth. His Ferrari may be borrowed, he may have borrowed money to buy the yacht, the trophy wife may really be in love with him. While we could say that the guy looks like a millionaire, these outward signs do not make him a millionaire.
The only way we will know if he is a millionaire is if he shows us the statement (which can be verified) of his assets, with assets minus liabilities coming to over a million dollars. That is what defines a millionaire, not whether he drives a Ferrari or a pick up truck (as Warren Buffet does).
Similarly, heartbeat, DNA, brainwave etc. these are manifestations of humanity, but they do not define humanity. As I have demonstrated, there are cases when there is heartbeat or there is DNA, but there is no humanity.
So one has to ask the question, what makes a human being? Scientifically, that is, I am not interested in spiritual claptrap. Until we can settle this question, the fact that fetus has a heartbeat, or human DNA etc., these things really don’t mean much.