"I can see no difficulty in a race of bears being rendered, by natural selection, more aquatic in their structure and habits, with larger and larger mouths, till a creature was produced as monstrous as a whale,"<quoted text>
I'm not sure why you're not understanding this - abiogenesis is the necessary prediction of our sciences, including but not limited to evolutionary theory.
(I wrote the word "necessary" on purpose, so that you could nitpick it)
However, abiogenesis doesn't form the basis for any of our sciences, for multiple reasons:
1. It's not been demonstrated
2. The processes, if any, are not fully understood.
That's simply not enough to form a foundation for contemporary theories of science. Hence, our theories predict abiogenesis and not the other way around.
We'd have to rethink our sciences to include how abiogenesis is not true. If it turns out there's some kind of divinity/non-material agent involved, every framework theory would need to be fully remade.
You mean "unpredictable variation," but "random" will suffice for shorthand.
Not necessarily - it would depend on how the external agent designed life. Perhaps it chose "random" variation and evolution to do its creating.
I don't think you could give up any assumption w/out knowing what the designer wanted, how the designer designed. Unless you have some insight into "it," we really wouldn't be able to make any claim - any claim. We would have great difficulties narrowing down causes for any phenomena.
Sorry, you haven't convinced me. How does evolution require abiogenesis?
It's quite clear how it predicts it - no creators involved in any of our sciences.
--Charles Darwin. Originally in The Origin of the Species, removed due to ridicule.