When does life begin?

Here's a news story that brought back an interesting thought that I've had a few times. It's about how Young Labor won't accept any collaboration between their mother party and the Christian People's Party (KrF) because the latter call abortion 'murder'. That's what the news story is about, not the interesting thought. :-) This is the thought:

I started thinking about it again because of course, as anyone could predict, a fundie or two has already popped up in the debate section of the article, saying that life begins at conception and so on. This is something that a lot of fundies believe. And I have heard a number of them say that all life is sacred and even if it's just been conceived like right now, getting rid of it is still murder, because the soul entered the ... creature, I guess, at the moment when it was conceived, so it's just as valuable as any fully grown human being, you or me, whoever.

OK, so, if these people really believe that, do they also believe that identical twins only have half a soul each? Since the little lump of cells doesn't split in two immediately, but after some time, at least a day, I think ... usually several days ... and the soul by then has already entered it, according to these people ... wouldn't each twin have just half a soul? Or if it's triplets, then they'd only have one third of a soul. Or, ooh, the Suleman octuplets!! They would only have 1/8 of a soul each. What's the point of having just a tiny little bit of soul like that - they ought to just sell all of 'em, they could sell all their eight parts to one set of twins, then the twins would have 1/1 soul each and the octuplets probably wouldn't even notice, I bet, since they had hardly anything to begin with anyway.

I know, this is totally messed up, right? You'd have to be crazy to be thinking like this. Yeah.