One assertion Artemesia made in defense of her hypothetical strikes me as especially untrue:
A parent has a choice about whether to continue the parenting relationship. But most importantly, there is a fundamental difference between being required to donate one's biology and being required to donate one's external resources.
Artemesia asserts there is a fundamental difference between being required to donate one's biology and being required to donate one's external resources. I disagree. What's the fundamental difference? To have and use external resources don't we have to use our bodies? Aren't external resources the products of our biology and its use? To care for their children, parents have to use their bodies in a variety of ways or else their children won't survive. Wouldn't it be wrong for me to let a child in my care starve because I didn't want to use my bodily resources to get her a bottle of milk? Yet Artemesia seems to disagree when she says, "any human being's right to life ends when it requires the biology of another human being in order to stay alive."
A pro-choicer could argue that parents can make an adoption plan and therefore parents don't need to provide their bodily resources as Artemesia does when she says, "Parents can terminate their relationship with children by giving them up for adoption, giving them to the state, or having them raised by relatives. The child can survive without any particular person."
But wouldn't giving a child up for adoption require basic bodily resources? A parent can't just think "I'd like to make an adoption plan for my child" and then it suddenly happens. Parents looking to making an adoption plan have to use their bodies in a variety of ways to accomplish the task before them. At the very least, they'd have to use their bodily resources to make a telephone call to a state or adoption agency, talk to someone from that agency, wait for a period of time and still care for the child in that period of time, let the agency people into the home and sign numerous forms. In one way or another every parent has to provide their bodily resources for a period of time whether they are raising a child or making an adoption plan.
A world where "any human being's right to life ends when it requires the biology of another human being in order to stay alive" is a world that none of us would want to live in. Imagine a world where no human being is required to do anything with their body when the life of another human being is at stake. At multiple points in all of our lives, during gestation and afterwards, we all required the biology of another human being in one way or another to stay alive - be it when we needed someone to feed us, be it when we went into the water before we could swim, be it when we wandered to close to the street or be it when we first started to drive.
A world where every human ceases to deserves legal protection because they require the biology of another human to stay alive is a world where humanity ceases to exist.