What would falsify evolution?

This is a bit difficult, because evolution has already been so thoroughly tested that it’s hard to come up with predictions -- they tend to be postdictions. That is, things that would falsify it, but which we already know aren’t the case.One could take any of the lines of evidence for evolution, and reverse it: ‘if evolution were not the case, we would / would not find... do[/I] / don’t find, which is hence evidence for it’. That is, not finding the evidence that we do find. For instance, if human genetics had been entirely different to that of other apes; finding some mammal species that uses uracil in place of thymine in its DNA, perhaps. Or maybe humans having retinas wired the cephalopod way. But we already know these aren’t the case.It’s worth noting however that these are postdictions now, but they didn’t use to be! Any of our modern knowledge in these areas could have undermined evolution.Also, evolution is a theory of pattern, so finding a single anomaly would not necessarily falsify it. But conversely, a radically different pattern would falsify it completely.But here’s some of off-the-top-of-my-head prediction -- things that might still turn up, in principle.Undoubtedly Precambrian (ideally, though Cambrian would do) mammalian fossils. Note, plural, because this is about pattern. If mammals were generally found before there were even amphibians, it would be pretty inexplicable. Bat fossils have been found in the fine-grained Messel oil shale; perhaps some might turn up in the Burgess shale too? Note that you’d need later things found before their ancestors, not the other way round. I am flummoxed as to how ‘living fossils’ are supposed to refute evolution.Biogeographical anomalies -- apparently ‘closely-related’ and pretty immobile organisms found on different continents, something like Orchidis prettiflowerii subspeciesalpha in India and Orchidis prettiflowerii subspeciesbeta in North America. Or species of lizard on a 4myo volcanic island in the Pacific whose nearest presumed relatives live on islands off the west coast of Africa. Again, an odd case might have some explanation within evolution; but a large number of examples would be pretty damning. After all, evolution is the reason for the biogrographical distributions we see, but there’s no reason -- other than that -- why prehensile-tailed monkeys, say, should only be found in the New World.Features matched purely to their function, not to their lineage. So a bat with avian lung ventilation, not it’s mammalian one; a new whale species with fishlike gills instead of lungs, and so on.Finding any new species -- and there’s plenty out there to go find -- whose genetics was radically different to anything else. Specifically, some ‘higher’ organism, which in principle should be related to something already known, that has completely different genetics to the known species.The utter non-matching of non-coding DNA between morphologically similar species. The coding stuff should be similar perhaps, because it builds similar bodies. But the non-coding stuff -- which is easily most of it -- has no reason to be similar.Observation of... oh, pick your own creationist caricature! ... a dog giving birth to a cat, or something. Or marginally more plausibly, a fish egg developing into a salamander.An earth that did turn out to be mere thousands of years old; a universe a mere million, etc.A mechanism for making offspring that prevented mutations; the observed mechanism for descent that made accumulation of mutations impossible. (Not sure what that might look like, but it’d prevent evolution.)And here’s a couple of links on this sort of thing (though I think my list above is more comprehensive than these!CA211: Evolution falsifiable How Fossil Evidence Supports EvolutionHope that helps!Cheers, DT

Ah, Quetzel, I know I can always rely on you to know what you're talking about, even if I don't! I know biogeography is an important -- and often overlooked in these discussions -- strand of evolutionary theory, but I do tend to make it up as I go along when I want to redress that balance! Thanks as always!The point of course being that if something is a falsification, it will be inexplicable according to the challenged hypothesis. Presumably the Geochelone and Trochetiopsis examples are not inexplicable...? IOW, there are perfectly good reasons why these things are where they are. That's better! Heehee! Careful there, Q. Isn't it nigh on a law of ecology that two species cannot share the same niche (at least, not for long!)? For example, red and grey squirrels... DT

Brian, I'd suggest a thorough browse in the TO macroevolution FAQ that Paul has linked you to. I forgot that that FAQ has a 'potential falsification' for each point discussed, which should cover everything you need!Cheers, DT

That's not a nitpick, that's a better phrasing of what I was trying to say!(Seems that 'off-the-top-of-my-head' is dangerously close to 'pulling it out of my arse'... )