Can you give me an example? Evolution is mainstream science these days, the overarching frame of biology, and its essentials are not only unrefuted, they're not under any critical pressure at all. Details here and there are matters of debate, but that's true of all science as we advance.
Again, an example would be helpful. As you say, abiogenesis is a totally different topic to evolution, and at present there's no demonstrated path from chemistry to living biochemistry, but there have been steady advances, and I expect to see such a path demonstrated in my lifetime.
I guess a 'gross extrapolation' is something we know when we see it, rather than a definable state, but this is why specific examples are helpful.