There’s neither scientific fact nor biblical teaching to support this position though. I often see “Thou shall not murder” as a defense for antiabortion policies, but it takes an unsupported leap to call it murder to begin with. Genesis says that life begins at first breath, which is far after most societies consider abortions legal and moral.
There’s also no indication that people even used to think that life began in utero, and that anything less than a fully formed infant was alive and capable of surviving.
What "science" says is that we can keep a fetus alive that had the misfortune of being born at... 24 weeks, I think? But the number keeps moving - it used to be 28.
So at least at some distance after conception, yes, medical science supports seeing a fetus as a human, with life of its own.
It says no such thing. It says that Adam's life began upon first breath. Adam was also created as a full grown man, so it's clearly not an example for human life as a whole. The Bible doesn’t teach that every man comes to life at first breath any more than it teaches that every woman comes from the rib of a man (from https://www.str.org/w/does-bible-teach-life-begins-first-bre...)
The Bible does say, in multiple places, clearly imply that life begins in the womb. For example, when John leaped for joy in his mother's womb, announcing the coming of the Lord.
There’s also no indication that people even used to think that life began in utero, and that anything less than a fully formed infant was alive and capable of surviving.