First off, a comment. Those who are typically most concerned about the title question are those who are trying to discredit evolution because it trashes their belief system: creationists. Thus the people who would most benefit from this topic and the underlying information are the people who will never read it, because their worldview requires that they remain defiantly uninformed – apparently god is vulnerable to a decent argument. So I know there’s no hope of reaching any of them, but as it says in the Welcome page, part of the purpose behind this blog is to organize thoughts and get some practice in writing; if at some point, I reach someone else with something they find interesting or useful, excellent. But I’m under no illusions that this is guaranteed, or even likely.

So on to the question: what would prove evolution wrong? And by this I mean, since ‘evolve’ doesn’t have to refer to species, how could the theory of common descent and natural selection be shown to be false? But let’s get a little misunderstanding out of the way first. ‘Theory,’ in scientific usage, does not mean anything like ‘best guess’ or ‘pet project,’ and it is not part of the progression ‘hypothesis-theory-law’ – I was taught this in school too, and it’s dead wrong. A theory will never become law, since a law is the observation of physical properties, usually able to be expressed mathematically. A theory is an explanation for the observed physical facts; the facts are an overturned houseplant and marks that look like cat footprints in the spilled soil, the theory is that the cat did it. The more facts we find that fit with the theory, the stronger the theory is, yet there will never be a law of, “the cat did it.” With natural selection, the supporting facts number into the millions now. Not to mention, the theory also predicts, telling us what is likely to be found and how we might combat illnesses and such – this is hardly weak, or an example of dogmatism in science.

[A quick side note: dogma, which religion relies on and would probably cease to exist without, is somehow considered by religious folk to be a bad thing if it crops up in science. Yeah, this kind of hypocrisy occurs constantly.]

Now, disproving a theory does not make any other theory fair game for consideration (much less a ‘default’ conclusion) – it has to fit the exact same facts. So there’s really two different topics wrapped together. It is perfectly possible to discredit natural selection in its entirety, but this has no effect, positive or negative, on any other theory at all – nothing gains strength through the weakness of natural selection. Moreover, natural selection would not even have to be discredited for any other theory to be considered – for some reason, people seem to have this, “There can be only one” idea, but it’s possible to have multiple theories for the same conditions, and we do, in areas such as quantum physics and cosmology. So that means the second part is establishing the strength of any other theory – same facts, better predictions, better demonstrations of accuracy and understanding.

So to compare facts against the theory, we know that genetic traits can be manipulated and selected, because we’ve been doing it for centuries; we would not have most or our current fruits and vegetables, most of the dog and horse breeds, most decorative flowers, and hundreds of other items, without this. So change of some kind is distinctly demonstrated. Natural selection is simply the idea that the environment can also serve to make these changes, only much slower – if a critter that develops more leaf-like appearance survives longer, those gene variants will probably gain greater numbers in subsequent generations. This hardly needs to be demonstrated because it’s simple probability, but nevertheless, it has been shown to fit by the careful study of genetic lines within species, and in fact, we have this down fine enough to actually produce genetically-modified organisms (GMOs,) which takes the whole selective breeding thing at the beginning of this paragraph to a whole new, very specific, level.

Genes also provide a supporting statistic in their mutation rate. It is the mutations and ‘drift’ (along with recombination of male and female parental genes) that allow a descendent to be different from its parents, and by knowing the rate that this occurs on average, we can actually trace back a timeline, especially to a point where two species diverged from a common ancestor. The frequent claim, by the way, that there hasn’t been enough time for the changes to have occurred is nonsense – there’s been more than enough time given the demonstrated mutation rates.

Supporting this method of generating a timescale is the fossil record, which fits tightly into the genetic timeline. When we look at chimpanzees and gorillas, comparing their genome to our own, we find a distinct number of differences, most of them in stretches of DNA that produce little or no affect in traits – the so-called ‘junk DNA.’ These stretches, untouched by environmental pressures because they produce nothing for the environment to act upon, serve as a genetic clock to count backwards to the point where all three species had a common ancestor. The fossil record matches this very well, as our predecessors and those of the other great apes converge in traits and appearance towards one another. The fossils, by the way, are dated through multiple means, including demonstrated sedimentary deposition, radio nucleotide decay, plate tectonics, and even ice core samples; again, the more facts that converge on the theory, the stronger the theory is, so we’re pretty solid on these dates all tying together quite well. If the entire theory is wrong, then which part of it is wrong, and why does this wrong portion still fit with all of the rest? If they’re all wrong, how do we know? What’s right instead, and how has that been proven?

The fossil record also demonstrates natural selection throughout its range, which is 3.5 billion years. Everywhere we look, every fossil found, shows the progression of traits we should expect, from the simplest forms to the more complex, from the development of limbs to the migration according to climate, from the sudden loss of hundreds of species during an extinction event to the development of new ones from the survivors following. And I have to include a small side note for perspective: we did not have fossils when the theory of natural selection was developed by Darwin and Wallace. Only a handful of finds had been made and noted, but they were all considered anomalies. The plethora of extinct species that we have now were nearly all found after the theory predicted their existence – the theory was and is, in fact, the primary motivation towards searching for them in the first place. Their nonexistence would have weakened it remarkably.

So, for natural selection (which is at heart a very simple function) to be falsified, we’d have to find something that was responsible for all of these data points and millions more on top, that explained viral mutations and antibiotic resistance and vestigial organs and similar skeletal structures among widely disparate species and DNA similarities and ontogeny and on and on and on – all data which we have at hand. We’d have to show that natural selection (with its underlying reliance on probability) was not responsible for the myriad forms we have today, and can even watch develop. In short, it would have to act exactly like natural selection without actually being it.

The first salient point about this proposal is, who cares? If there really was a new theory that could take the place of natural selection and common descent, fine, so be it. It would still have to predict solid results, and that’s the whole point behind a theory in the first place. Second, as mentioned above, it does absolutely nothing to accommodate the efforts of those who want to dismiss evolution, because what they want in its place is special, directed creation – a god. And it is necessary to be perfectly blunt in here: there is no evidence for this idea. At all.

Faced with all of the bits enumerated above and many more on top, the creationist response is to claim that none of them are interpreted correctly. That fossils are planted by god just to test our faith, or examples of species that all died in the flood. That at the same time, all of the dating methods we use, that interact and overlap, are all wrong. That genes don’t actually indicate common descent, or would have taken too long to produce changes. That the breeding that we’ve been doing for centuries, even recognized in many forms of scripture, produces changes in traits, but not species (the micro and macro evolution distinction, one that exists only semantically and not physically.) That all, or nearly all, of the fossil hominids that we’ve found count as apes and are thus not part of the human family tree. And on and on. The most salient fact of all this is that none of it is enumerated, at all, within their scriptural sources of information – it is, in plain fact, mere speculation. Which would still be all right if the facts bore it out, but they don’t.

Then we come to the really damning bit, which is the necessity of a competing theory – it is not enough to call something into question (even if accuracy were present); for the alternate explanation, creationism, to be worthwhile, it must be able to explain at least all of the above facts, as well as having a coherent structure in the first place – fair’s fair, after all, and the same rigorous standards need to be applied everywhere. Ignoring, just for the sake of the broad posit, any and all scriptural accounts and going only with directed creation as a theory, we must define in what way this is differentiated from non-directed physical laws. The big difference is, of course, intent, so, what is the intent? Nobody has yet answered that. Add on, who or what possesses this intent, and you get a bunch of vague replies, all of which claim properties outside of evidence, tests, or even existence in this universe or set of dimensions. That this once again brings us to exactly the same result as natural selection is usually lost (or conveniently ignored) – it does not produce any different results, makes no predictions, and cannot be tested. This is not even a theory.

Opening up the big box of scriptural sources for even proposing this concept in the first place, and we find so much incorrect information, so many failed predictions, so many inconsistencies, that now the only rational response is, “Oh fucking please.” Even the faithful adherents, heavily invested in this somehow being plausible, cannot reach any agreement on conditions or details; there is not one theory, but a million of them. Some posit a universe only a few thousand years old; some posit that their god created all the rules as we see them. Some posit direct intervention, as in, miracles; some posit a ‘ground of being’ and vague spirituality that cannot even be defined. None of them can offer a useful explanation as to why the recurrent pharyngeal nerve, going between the brain and the throat in mammals, loops down into the chest cavity and around the aorta, or why humans are sometimes born with tails, or why radiometric dating matches so well with sedimentary deposition.

And then we return to the prediction part, and the predictions of the creation theory are, well, not much – judgment some day, though when this is to occur has been interpreted and reinterpreted so many times that it’s laughable now. But as for biological predictions, or what we might expect to find, or how to use this to our benefit? Zilch, nada, nothing, bupkiss – while we can (and do) use natural selection to predict fossil finds and virus mutation, perform gene splicing and determine what kind of organs can be transplanted, and on and on. We use it because it works, better than anything else yet proposed, and still remains quite simple.

[Another quick side note: while we knew that something carried information from a parent to offspring, the basic concept of genes, we had no idea what DNA was at the time common descent was proposed; when discovered, it fit with the predictions, but offered a few surprises on its own, including trashing the idea that the pressures an organism faced during its life could be passed on to the offspring, usually known as Lamarckism. What we found is that the genes are not altered during the life of the organism, and can only change by chance when they duplicate in reproduction.]

So with all that, it really doesn’t matter what would prove evolution wrong, as demanding as that would have to be; we still have the bare traits of life, the fossil record, the predictions, the genetic compatibilities, and all those related facts, and nothing is going to make them go away. Meanwhile, it also wouldn’t make any form of creation more plausible in the slightest – that would take a whole lot more facts to support it on its own, even if we had no such concept as evolution at all. That search has been going on for a few thousand years now so, uh, best of luck with that. Thankfully humankind can keep moving forward without them.