Hypotheses don't become any less Popperian if possible falsifications also falsify other hypotheses. Think of your own chosen example from Ruse of "planets moving in squares". I don't know how many hypotheses that would falsify, but we could probably give the whole set an umbrella description like "cosmology"!
That would seem to eliminate the utility or purpose of Popperian falsificationism though, wouldn't it? Indeed, I suspect that if extrasolar planets were to be observed orbiting in squares throughout much of the cosmos, then the RNA World model would be falsified, as would lithopanspermia (as such an observation would have profound implications on physics and thus chemistry).
Nor does it seem to be a notion that Popper ever espoused, as all his examples of the application of falsification -- e.g., Einstein's theory of relativity -- dealt with predictions made specifically and exclusively by Einstein's theory.
Well, you're the big Popper fan. Does this mean that you consider Kepler's laws to be improperly constructed? When I suggested that RNA could have turned out to be far more unstable than it actually is and incapable of supporting life in any circumstances, was that hypothetical falsification less plausible than "planets moving in squares"?
I agree that is problematic, but that is not what I am contending here. First, I am arguing that the lithopanspermia hypothesis should be considered as a "properly constructed" -- that is, Popperian -- scientific hypothesis, by virtue of its falsifiability through phylogenomics.
There might be problems with that. Firstly, you seem to regard the hypothesis that a simple organism without complex radiation protection could be sufficiently protected in some meteorites to survive a transfer as being both falsifiable and falsified, because you're treating the opposite as a fact. Are you sure of this? Then there's the Fuca - Luca problem you've been discussing with others. However, whatever the value of your suggested falsification, lithopanspermia is a perfectly respectable scientific hypothesis that has already passed falsification tests (it could have transpired that all organisms would have been destroyed in space).
They're definitely falsifiable.
You may very well be right; however, I have yet to see a compelling, detailed falsification scenario for the RNA World model, so consider this your opportunity to present just such a scenario.
You certainly haven't seen a compelling, detailed falsification scenario for the hypothesis that life exists off this planet yet, but it doesn't stop you assuming it without testing, does it?
As you like the historical approach, this abstract actually claims to have falsified RNA world.
Based on the arguments you and Dr. Adequate, and others, have presented here, I concede that the RNA World model for the origin of life is falsifiable. I suspect that the metabolism-first model is perhaps more difficult to falsify, but I can imagine scenarios where it could be considered refuted.
This means the core argument in my OP has been knocked down. However, I would like to see exactly how you view the whole issue of Popperian falsification. Simply put, given that you don't seem to be particularly enthralled by Popperian falsificationism, what -- in your view -- is the proper place of Popperian falsificationism in the broader fabric of science?
This means the core argument in my OP has been knocked down.
It's gracious of you to say so (it's rare to read a phrase like that on EvC!).
We could have a Popper thread, but then I personally don't like the idea of reading his science related stuff beyond short extracts.
I'm sure that you'd get participation if you wanted to start a thread on falsification, which is certainly a valuable concept, whether I'm enthralled by Popper or not.
Thanks for the O.P. anyway, and for an interesting discussion. Panspermia is definitely good science, anyway. I'd be surprised if it hadn't happened somewhere in the universe at some time, whether it's part of our own story or not.