Evolution and the Plausibility Problem

This is a complex enough essay that I’ll tell you my thesis outright:

Evolution proposes a mechanism for how complex life developed and then attempts to make it plausible by appealing to vast time and a colossal universe. But this is naked assertion until the probabilities can be defensibly estimated and known. Multiplying unknowns by larger numbers does not solve a probability problem.

Introduction

The need for evolution as a mechanism arises naturally enough from the ordered creation. The complexity all around us demands an explanation. Order and structure naturally support a Creator rather than bare chance (Psa. 19:1; 104:14, 19; 147:4–5; Prov. 3:19; Jer. 10:12; Rom. 1:19–20). In fact, prior to Darwin, deism was the best option available that could both explain life and also move God to the margins.

But Darwin offered a new and better framework to explain this order without the need for any Creator at all. If the more well-adapted life forms are more likely to survive and reproduce themselves than the less well-adapted, we might just manage to get to complex life without God. Natural selection is a hypothetical mechanism outlining how that would have happened.

But is it Plausible?

As with any theory, the burden of evidence is not just for a possibility but plausibility. Proposing a pathway for how something theoretically could have happened isn’t enough; it must also be a reasonable one. All theories must grapple with the merciless math of probability.

Creation by divine fiat is inherently plausible given a theological framework, and it fits entirely with God’s nature. He can do whatever He wants to do (omnipotence) and has the wisdom to create a complex, beautiful, and ordered world (omniscience). Given how Scripture describes His nature, the complexity we observe in the world is exactly what we would expect.

Meanwhile, the plausibility issues with secular materialism are harder to overcome. Here, order is very much a surprise rather than an expected outcome. Evolution answers improbability by widening the scale. Given billions of years multiplied by the unfathomable number of atoms colliding, who’s to say that these things aren’t happening or couldn’t have happened? Roll the dice enough times and the most unlikely outcomes might become possible.¹

Humans are bad judges of plausibility.

Materialistic evolution extends the argument further. It stretches our imaginations to think that such an ordered world could have simply emerged. It’s also true that humans are rather bad at handling numbers at vast scales—we can’t wrap our imaginations around what a billion years feels like nor how many atoms there are in the universe (around _10⁸⁰?). And so it follows that our intuitions might also be off on the plausibility question. Said more simply, we can’t imagine the size or age of the universe, so our intuitions aren’t to be trusted on whether evolution is plausible either.

The situation is rather comparable to the Fermi paradox—if life could emerge naturally without divine intervention, why hasn’t it happened on other worlds? The universe is immense enough (₂ trillion galaxies and _10²³ stars) that somewhere there should be a planet with liquid water, stable temperatures and the right inputs for life to emerge. Stretch that out by 14 billion years and intelligent life should have emerged on at least one of them. The Fermi paradox extends abiogenesis (life emerging from non-life) and evolution to one of its natural implications—extraterrestrial intelligence.²

How to judge the plausibility of “?”

The Fermi paradox is a useful test case because the question likewise reduces to probabilities and plausibility. We could represent the odds of life developing on a habitable planet as exactly 1 / n. Perhaps the number of habitable planets is n or smaller so that life only ever happening here is exactly what we would expect.

Here the argument gets really interesting. We simply have no good way to authoritatively estimate the size of the universe or the probabilities of life developing. There is no way to measure the value of “n.” Without a meaningful way to count planets or measure probabilities, the claim that abiogenesis is plausible on some planet has to remain a naked assertion.³

But the plot thickens. Because it turns out that what is true of planets and universes is also true on the microscale. Whatever we have been able to learn about living systems (which is a lot!) we haven’t achieved exhaustive knowledge of a single living cell. In fact, we don’t even know how much or how little we know at this point. Like any sufficiently developed field of inquiry, answering one question raises many more.

And now we can return to the original plausibility question. Evolution proposes a mechanism for the increasing complexity of life.⁴ But has it calibrated the probabilities to answer the plausibility problem? If the likelihood of life developing on our planet is 1/n, is there any way to quantify “n”? Secular materialism will always incline towards maximizing our estimates—”we’ve answered many of the questions” and so on. But while we’ve learned a tremendous amount, key aspects of life systems continue to be a bit of a black box or a vanishing horizon, continually eluding our full explanation.

And on that basis, a purely evolutionary explanation for life cannot answer the critical plausibility question. Until we can reverse-engineer life or comprehensively explain the mechanisms of even a single prokaryotic cell, the probability of life developing on its own can only be 1/an unknown number. On the face of it, the assertion that evolution is not only a possible explanation but also plausible, is an unsupportable claim. Large numbers might solve a probability problem if we can estimate the odds. But larger scales don’t grant us warrant for ignoring odds altogether. In short, evolution finds itself in the awkward position of claiming that a specific set of odds becomes plausible given enough time and opportunities, when given our present knowledge, these odds are unknown. It claims that life is not too complex to have developed naturalistically, even while we are still unsure how much of the system we currently understand.

Conclusion

Surely, the same argument can be given in reverse. The notion of an eternal God with infinite wisdom and power creating a universe by the mere authority of His words will likewise strike some as implausible. And admittedly, if divine creation must be proven by the evidentiary requirements of bare materialism, we refuse to acquiesce. Some might call this our own plausibility problem. These are terms we are willing to accept. We only ask that those on the other side of the discussion have the honesty to do the same.⁵

“By faith we understand that the universe was created by the word of God, so that what is seen was not made out of things that are visible.”

1. As we will go on to argue, even at massive scales, math still matters. Evolutionary materialism argues that our intuitions are off because humans manage large scales poorly. That’s entirely true. But the sword cuts both ways. Humans are poor judges of probability at tremendous scale, but we will argue that evolutionary materialism has abandoned the plausibility question altogether by including fundamental unknowns in its calculus.
2. The Fermi paradox is not much of a defeater argument for evolution, however. There are various ways to answer this charge such as the supposition that the path to intelligence eventually leads us to developing powerful enough weapons that we destroy ourselves or that civilization consumes all of our resources and implodes or more optimistically, that truly intelligent life forms get smart enough to stay in their own neighbourhoods and mind their own business since for a super-intelligence there are plenty of resources to go around. One of the more interesting explanations is that super-intelligent galactic neighbours are merely voyeuristically watching us or may even have seeded life on earth as a gigantic experiment (panspermia).
3. Ironically, this argument was articulated by Richard Dawkins as a solution for the Fermi paradox or for the problem the plausibility question raised above.
4. Precisely stated, the living evidence we see around us requires two explanations—first the origin of life from non-life; then developing complexity from relatively “simpler” to larger-scale systems and intelligence. Natural selection proposes a mechanism for the latter. The former problem is largely ignored.
5. In fact, the two sides are not equal. Evolution posits for its own standards of evidence, materialistic and falsifiable data. The Christian faith posits for its epistemology the authoritative words of the living God. We have fulfilled our own standards of evidence; they have not.