You seem to be conflating the idea of a fetus with the that of a child that's already been born (or whatever you're trying to get across with your "dolphin" argument, I honestly don't understand it). The reality of the matter is that until roughly 22 weeks into the pregnancy, the thing that's inside a woman's body ISN'T human; or at least not a separate biological entity capable of surviving without being connected directly to the mechanisms meant to keep it alive inside the womb. Until that point, a fetus is effectively a grouping of stem cells that has no conscious thought or idea of what goes on in its surroundings.
My point with the dolphin analogy is that using intelligence as an argument is that an adult dolphin has more intelligence than a one day old, yet killing a dolphin isn't illegal. As far as not being a separate biological entity, that's true until birth yet nominally that's not how long until abortion is considered legal. The actual viability of premature infants is not as simple as viable or not viable, even with intervention. We don't consider those who die as not human. I will agree, though, that being biologically linked is a clear distinction, but I wonder what our standard will be in the future if we develop an artificial womb capable of supporting a fetus from even the earliest of stages. Will abortion still be a legal thing, or will we mandate a transfer to an artificial womb?
And saying "it grows into a human" is simply a non-argument, due to the fact that not only are there many times throughout the early pregnancy stages where a "fetus" could self-terminate without the mother even knowing (a prime example of this would be a fertilized egg dislodging from the uterine wall and leaving the body with the next period), you're also effectively saying that every sperm cell and every egg has a right to life. Which is absurd, there's nothing that would classify either of those as "human," despite that they are what multiply into an embryo.
Neither a sperm cell nor an egg alone has the ability to grow into a human alone, so they're no more a human than a mole is. As far as self-terminating fetuses, there's also plenty of infants who self-terminate because of congenital defects. We don't consider them non-human. I think it's disingenuous to conflate self-termination through a biological process with intentional termination through an outside process.
You're implying that the responsibility of taking care of your birthed child is in any way equivalent to the involuntary process a woman's body goes through to develop offspring throughout the stages of pregnancy; it isn't.
Nominally, the process of pregnancy makes you responsible for the birth child, for which we have a standard legal process of alleviating oneself of that responsibility of which murder is not a part of it. And nominally, the process of sex makes you responsible for pregnancy--rape excluded, although some would also include birth control failures--, for which we have a standard legal process of alleviating oneself of that responsibility of which murder is a part of it. If you prefer manslaughter or some other term, that's up to you.
You seem to think that the idea you're proposing is absurd, when really it's quite practical. I don't see why you brought pigs into the argument, though
It's not that I think it's absurd. It's that we clearly don't hold this standard universally. Until we do, we're conveniently using intelligence as a standard and ignoring it when it's inconvenient.
Sure moles don't grow into separate human beings on their own. But actually it's possible to create a human being from a mole. You can insert the nucleus from a mole in an unfertilized egg and produce something capable of becoming human. Further - if you supplied the right growth factors to a mole cell itself you could ditch the fertilized egg entirely.
Now let's talk about a sperm. Given the right circumstances it too can create human life. Does it matter that it's only one half? Should we be concerned with protecting the life of a sperm?
If you actually create a human from a mole and implant it into a womb and it's at least as probably viable as one nominally created, I'd say it's a human. If the odds of a human being born are astronomical, I'd tend to say it's not human. Taking a viable embryo out of a womb makes it non-viable, and when it's a conscious act, then it's murder/manslaughter/whatever. With sperm: it can't alone produce a viable human and even introduced into the vicinity of an egg, it's not guaranteed to fertilize it. Knowingly terminating viable fertilized eggs in a vial before implantation would not be murder, I guess. I'll readily admit it's a gray area, like a lot of questions are. But putting out hypothetical could-be-made-into-a-human isn't reasonable anymore than was-going-to-die-eventually-anyways to say whether something is human or not or something intentional terminated is human or not. Regardless, it should all stay legal because it's currently the most acceptable pragmatic choice.
Anyways, that's the general gist of my feelings.
