Life doesn't start at conception though - both the gametes are, in a very real sense, alive. I agree that conception is the point where the potential for a new and distinct human life begins but it isn't the start of life itself - I'd put that at the point where significant/meaningful brain activity starts.
I think that, up until the point where the two entities couple, the sperm and eggs are akin to blood cells of their respective host at their origin. They originate from another source of host body material like how blood develops from marrow. Allowing a sperm or an egg to die is like allowing a blood cell to die. White blood cells even move around, and do things other than haphazardly float around. A cell can equal a human... but unless they are coupled they do not.
What is "significant/meanignful brain activity?" Does that occur in the womb? Do we set the start at birth? We don't develop our personalities for years. Does that up until our personalities develop we are nothing but poop machines that can be aborted? ...I guess that one would've been Miss Anthony's mindset if she actually did it.
Does someone have to be a sentient autonomous individual to be considered human?
The new potentially viable human's life starts at conception. Life isn't brain waves. Plants are alive, and they have no brains. The standard doesn't change from species to species. We are a certain type of organism. We have a life cycle. The cycle effectively starts at conception. A sperm by itself does not continue to grow and differentiate. An egg by itself does not continue to grow and differentiate. (the last two statements are from what I think I know... you might be able to force something to do otherwise...but as far as I know, it doesn't happen naturally). The cycle can't truly begin till the two halves come together. I guess we'll differ on the issue of the sperm and eggs being akin to blood cells (belonging to the creator of them or being their own entities). Up until they couple, the two separate entities only have DNA of their respective creators(aside from random mutation that occurs in all cells). Once they've coupled, their DNA is no longer of any one source. They have their own unique blueprint (twins aren't even exactly genetically identical).
With regard to the natural abortion thing... maybe you can view it like a butterfly in a cocoon. It may or may not make it on its own, but you shouldn't smash it before it gets its chance. People view the zygote as it's own human just starting the cycle of life, and they think that all human life should have the chance at life. It is the zygote's responsibility to weather the storm of incubation and remain viable... just as it is the butterfly's responsibility to force its own way through the cocoon. The position is that you shouldn't make incubation impossible to weather.
Saying that all life is precious and nothing should be killed is pretty... but impossible. ...as we and all carnivorous and omnivorous animals live at the expense of the lives of other organisms. I acknowledge that there are circumstances that permit such a procedure. I know that it isn't as easy a decision as some of this implies ...but I see some of it as a waste of life.
I think your position is that a fetus isn't developed enough to merit a right to life... is that correct? I mean why start the right to life at beginning of brain function? We aren't a full fledged personality till around our teenage years? I'd imagine that reaching that milestone would be different for everyone. ...so why not have them psychologically evaluated? If they fail, then we can euthanize them, and if they pass, we get an MLB umpire to stand beside them and go "YOU'RE SAFE!!!?"
As I've said before, the one part of the one organ you claim makes someone alive, doesn't even have that much or anything to do with keeping someone alive. With brain dead individuals, it seems to be that their personality is gone and the body remains, so we can justify an abortion off of that because they don't have a personality? The difference between the two is that the brain dead person is gone, and that hump of flesh won't ever regain a new persona(if they get it back they were never really completely dead... >_> even if it's altered). The hump of flesh in the womb will eventually have one. I've seen seen abortion justified off of the lack of a personality with reference to brain dead people. Also, the gov't isn't going to say that brain dead people are to be kept alive... this is because they'll have to provide the money if and when the family stops paying to keep it alive.
If you want an abortion on the grounds that the thing inside you isn't alive and you don't want it, then you have done very poor reasoning. The thing inside of you is very much alive. If you can admit to it being a human being, then you should be allowed to have such a procedure. I say the word human being is synonymous with Homo Sapien Sapien... or whatever it is that we're called nowadays. I'm sure there are new definitions like there are for gender. Art pieces also have personality, tho... Does that mean my thinking the human being in all stages of life is a work of art gives it personality? ...well everyone else seems to think that applying new or random definitions/interpretations of the same word to a phenomena makes it so. (although that one is slightly more random)
I understand the "my body" argument, but I feel that you need to be able to admit that your abortion is going to kill an organism. It isn't the termination of the pregnancy that people have a problem with. It is the termination of the life. As I've said, life has many stages. Not all of them are "human" and personality related. If we could somehow move the zygote/fetus from the womb to some sort of incubator that allowed for a safe gestation period, then I would be all for abortions.
I find it odd that on this... the day of my AG birthday... the very same thread that I entered the forums on would resurface and I'd make a comment in it. ...except there's no 1 arming organic chemistry 2 and Organic chem 2 lab for 5 weeks because of a bursectomy 4 days earlier. Gawd that was a terrible period. I wanted 1000 forum posts by this... the day of my AG birthday... but this resurfaced thread (I'm pretty sure it's the same one) has done more than make up for muh shortcoming...nostalgias