26 pages of running in circles.
Pro-lifers: what this argument keeps coming back to is your definition of a human being. The point that's being contended is that it is not murder to abort a foetus, but the justification for that point is that a foetus is not considerable a person. Now, this is about abortion in principle; many pro-choicers are in fact in favour of a reduction in the timeframe abortions are legal, so pointing at a late stage of development and concluding that a foetus by that point is a human being with rights ignores massive complexities and dismisses the possibility of earlier stage abortions without addressing why they're bad too. It's a complete strawman argument.
When does a fertilised egg become a human with the right to live and why? This is the true crux of the debate. The religious will automatically run to the sanctity of life as their explanation. People who do so shouldn't be debated in a scientific setting, as religion, as everyone will agree, is not scientific and not subject to debate. The proper response to the 'sanctity of life' argument is: 'I see. You're religious.'
Any argument beyond that is in fact an argument about the validity of religion and completely derails the topic. It's one you're free to have, but see it for what it is.
Any person who wants to continue arguing outside of 'Biblical evidence' must come up with empirically verifiable reasons for arguing what they argue. DNA is a meaningless topic; it is simply an entity in the mechanism which leads to protein synthesis. It's not even a valid point, and is purely an emotional one where people whip out percentages, as if that has some bearing on the subjective experiences of an unconscious organism.
The argument of a 'potential life' is another invalid topic; yes, an embryo foetus which was aborted probably would have become a human being had it not been aborted. However, it didn't. Therefore there was no human. It's effectively an admission that the foetus is not subjectively a human but rather an organism which will someday become human. However, this argument makes the presumption that the natural or most probably course of events without artificial interference must be the preferable course of events. That argument is quite frankly akin to saying that it's immoral to warn somebody of a volcanic eruption you predicted using instruments. They are both likely potential scenarios; to distinguish one from the other involves acknowledging that the value of probable outcomes per se is nil.
In a nutshell, 'potential lifers' shouldn't be argued with because the mindset they come from is very similar to religious dogma.
The only, and I mean the only point worth discussing is when a human being IS a human. Not when something resembles something that could become human.