Evolution by Natural Selection Better Explains All Current Life

Chapter 12 of John Loftus’ book, The End of Christianity, is titled: “Neither Life nor the Universe Appear Intelligently Designed.” It’s written by Richard Carrier, a brilliant scholar known worldwide. Here is an excerpt from Carrier’s essay.

Bool: The End of Christianity, edited by John W. Loftus

Ever since Charles Darwin proposed the theory over a century and a half ago, science has multiply confirmed in countless ways that the apparent design of all current life is wholly explained by a process of evolution by natural selection carried out on a vast time scale.10 And that is not NID [nonterrestrial intelligent design/AKA God]. All of this evidence is vast, and vastly improbable on any other theory, to the point that now it’s simply an established fact in our background knowledge. So the complexity of current life shouldn’t even make anyone’s list of candidates for NID. Nevertheless, antiestablishment diehards persist in insisting the contrary.

I’ll set aside ignoramuses who don’t know what they’re talking about and don’t even try to know (like young-earth creationists who think the Kentucky Creation Museum isn’t lying to them), and consider only actual scholars with PhDs in some relevant field who insist some current life proves NID. All their arguments amount now to various iterations of the same general claim: that there are at least a few biological structures that can’t have been formed even by evolution, and thus must have been formed by NID. Their argument is covertly Bayesian: they are saying the probability that that evidence would exist on a hypothesis of evolution is so small (whereas the probability that it would exist on a hypothesis of design is so high), that this overcomes any prior probability to the contrary. The most famous and representative example is Michael Behe’s claim that the flagellar propulsion system of the E. coli bacterium is irreducibly complex and thus cannot have evolved.11

These critics know (and when honest, admit) that many actual instances of very elegant and complex design in living things are not the product of intelligence but are fully and most credibly explained as the outcomes of gradual evolution by nonintelligent selection.12 Their existence is thus highly probable on the hypothesis of evolution, and in fact routinely far more probable than on NID—not only when considering their design flaws (which are fully explicable on evolution but less so on NID), but also considering what is far more commonly observed: evidence of DNA ancestry. That God would allow common descent and just “tweak” DNA here and there to build new parts and systems and species out of what’s already there, and piecemeal bit by bit over vast spaces of time, is certainly “possible” but is not even remotely what we would normally expect. The probability that a god would effect his designs that way, instead of any number of countless more direct and obvious ways (like simply creating all life tout court right at once, or just generating new species sui generis when it suited him), is certainly low, whereas the probability that this is what we would observe if evolution explained it all is fully 100 percent. Even Behe cannot deny this.

But the evidence weighs even more strongly against NID. Because our “evidence” includes the fact that life began as a single-celled organism, which continued evolving for over three billion years before it ever struck upon the notion of combining forces with other single cells to make a multicellular life-form. Once life chanced upon that innovation, all sorts of new opportunities arose, and life exploded into many different pathways of multicellular organization, yet even that took over a hundred million years to develop and finally settle on a few best patterns. It took hundreds of millions of years more for these rudimentary life-forms to evolve into the much more developed forms we see all around us now, and fully five hundred million years altogether for this meandering evolution of multicellular organisms to finally chance upon becoming a human being. And throughout this process, an initially simple chemistry of relatively common chemicals (just four nucleotide molecules) underlies the entire process with purely mechanical computer programs (strings of DNA) running everything and, as a result, frequently crashing or malfunctioning and acquiring bugs and garbage code and being copied incorrectly, and so on, all without any established sign of any intelligent programmer being around to fix or prevent all this, or even tending it in any way at all.

If there is no NID, all this is the only known way life could exist at all, the only known way we could exist at all. There is no other pathway by which random chance and natural forces could go from commonplace chemistry to human beings. Thus, given that we exist (which is a well-established fact in our background knowledge), the probability that we would observe the history and structure of life to be this way if evolution is how we got here is virtually 100 percent. But if NID caused life, then this is not the only known way life could exist. Quite the contrary, there are countless other ways life could exist and be structured and tended—not least being the most obvious: instantaneous creation of uniform bodies free of needless imperfections. Unless you can prove that no “very powerful self-existent being who creates things by design” would ever create life in any other way (in any other way) than exactly the same way that happens to be exactly the only way it would be done if there were no “very powerful self-existent being who creates things by design” to begin with, you must concede that the probability that such a God would do it that way, as opposed to some other, is less than 100 percent. Indeed, quite a lot less.

We must ask, for example, why plants and animals are constructed from colonies of single-celled organisms rather than uniform tissues. Evolution makes sense of the accumulation of cooperating cells, because any other pathway to current life is absurdly improbable. But if life is intelligently designed, why did the designer need to build tissues out of cells, each one identical to an autonomous single-celled organism, complete with a full set of DNA, merely programmed to act like it’s part of a system of many such cells together? And why such a slow, gradual process of development? Why have microbes inhabited the planet six times longer than multicelled plants and animals? Not only as opposed to all life appearing at once (again the most obvious thing we should expect on NID), but even the relative timeline makes no sense: again, single-celled life has been here, evolving, six times longer than all other life. As a product of NID, this makes next to no sense at all. God doesn’t need to wait. He has no thumbs to twiddle. But as a product of evolution, this is exactly what we must expect to see: because multicellular life then requires such an advanced development of cellular machinery, only an extremely long period of evolution could get life to that stage, thereby making multicellular organisms possible. Thus all this evidence is 100 percent expected on evolution. But its probability on NID is nowhere near that.

The nail in the coffin is Behe’s ill-advised emphasis on the flagellum of the E. coli bacterium. That flagellum actually belongs to lethal varieties of E. coli, an infamously deadly pathogen. We also have benevolent forms of E. coli in our guts, but even that becomes deadly if it gets into our bloodstream. Since the flagellum Behe says must have been intelligently designed is what gives this bacteria the ability to move around, it actually greatly magnifies its lethality to humans. In fact, that’s pretty much all it does—which means that’s what it’s for. In other words, Behe is essentially saying that someone genetically engineered bacteria specifically to kill us. This should be extremely alarming. If Behe wasn’t so obsessed with “liking God” for no good reason, he would be lobbying Congress to form a national defense plan against the terrorist threat he just discovered. We should be mobilizing to identify and protect ourselves from this unknown enemy filling the earth with deviously engineered weapons of mass destruction. That’s what any rational person would conclude from making such a discovery. But more to the present point, we must ask, why do bacteria even exist at all? Why have diseases of any sort, much less lethal ones so small we can’t even see them to defend ourselves? Evolution makes this observation 100 percent expected. The God hypothesis does not make it 100 percent expected—as if we could deduce with absolute certainty from the premise “there is a very powerful self-existent being who creates things by design” that “that being would try to kill us with genetically engineered bioweapons” (and yet still not do a very good job at it).

Behe would respond by insisting that, nevertheless, the existence of the flagellum is just too improbable on the assumption that evolution produced it. But it isn’t. And he hasn’t shown it to be. Because to this very day, he has never checked. He always counts up the parts of the machine itself, yet neglects to mention that the probability of those parts existing in that arrangement is fully 100 percent…given the arrangement of the DNA that codes for its construction (because the chemistry that ensues always produces that result mechanically from its coded input, no special intelligence required). And he can’t know if that code is improbable if he never even bothers to find out what it is. He has never engaged any scientific research to locate that code or determine its length or complexity. He has done nothing to find out if the genes comprising that code also already do other things in the same bacterium besides build the flagellum. He has done nothing to locate all the correlating genes in other microbes, microbes that also have flagella and microbes that don’t (as well as duplicate ancestral genes in the same microbe)—to see, for example, if there is any evidence of stepwise evolution in those genes across species, both in the ongoing evolution of the flagellum and in its evolution from prior organs or functions. He has never tried knocking out any of the genes or nucleotides in that code to see what happens or changing them to see how much variation is possible while still producing flagella or what such variations cause to happen other than the construction of flagella (which could be a clue to what that flagellum evolved from).

The fact of the matter is, the bacterial flagellum, though composed of barely thirty parts, is actually six times more evolved than the human hand (having had three billion years to our hand’s mere half billion), which is composed of billions of parts. Yet scientists have reconstructed a very obvious and well-confirmed pathway of small stepwise evolution from simple amorphous appendages to fully complex hands. If we can get to a billion intricately arranged parts from just one, using miniscule random steps, why does Behe think we can’t get to just thirty? Since there has been a vastly longer span of time for bacteria to evolve highly efficient organs like the flagellum, which, again, are actually vastly simpler than the organs we’ve evolved in just half a billion years, Behe has a long way to go before he can prove this couldn’t have happened. Thus, in actual fact, there is no evidence of his irreducible complexity. Because Behe has never even tried to find any, much less actually done so. No one has.13 So we’re left with all that other evidence, which is evidence we actually do have. And yet on any one of those points just surveyed, and far more so on all of them together, the probability that we would have the evidence we actually have is effectively 100 percent if evolution is true, but vanishingly small if NID is true.

Certainly, no rational person can honestly believe the latter probability is anything above 50 percent. There is simply no way the odds are “50-50” that “a very powerful self-existent being who creates things by design” would create current life that way, exactly the same way evolution would on its own, rather than any other way that’s far more sensible and expected. Yet that entails the Bayesian conclusion that the probability that God intelligently designed current life cannot be any higher than 15 percent (and is almost certainly a great deal less than that).14 That means no rational person can believe the probability that God intelligently designed current life is any better than 1 in 6. Which means every rational person must conclude God probably didn’t do that. Current life thus does not appear to be intelligently designed.